William McCollum

Manhattan Commercial Real Estate Broker

William McCollum

Senior Managing Director

Office 212-268-8290
Mobile 929-260-5148

Specialized Submarkets: Broadway / Chelsea / West Village / Flatiron / Fashion Center / Fifth Avenue / Noho / Penn Station / Plaza District / Soho / Times Square / TriBeCa / Upper East Side / Upper West Side / Wall Street

Bill McCollum, Senior Managing Director of Leasing at your service!

I joined Prime Manhattan Realty as the firm's Marketing Director in the spring of 2001, where I performed a dual role as the Marketing Director and Tenant Office Leasing Agent.

Working within these functions, I have developed my ability to find great deals & unique opportunities in the New York office market. Now as the Senior Managing Director and full-time Office and Retail Leasing Representative, I am offering you 12 years of commercial lease negotiating expertise and my services as a truly dedicated broker, searching relentlessly to find the best new properties for my clients.

Throughout the past 12 years, I have satisfied many fast growing business owners, leaving no stone unturned in finding the perfect new office. Whether Open Loft Offices, Traditional Offices in Class-A Luxury, or economical Class B & C buildings, with both sublets and direct leases. I also specialize in the commercial condominium market; my recent sale transactions as the buyer's rep include 8,200 sq ft full floor at 131 West 33rd Street and 3,400 sq ft at 70 West 36th Street.

Prime Manhattan Realty, in business since 1994, has represented thousands of tenants in finding the perfect NYC office space & negotiating the most favorable lease terms!


  • Frenkel International
    20 Broad Street
  • Engel & Voelkers Holdings US Inc
    430 Park Avenue
  • Online Trading Academy
    42 Broadway
  • Urban Engineers
    350 Fifth Avenue
more clients


We would like to take this opportunity to thank you for your excellent service in finding a new office for our company, Red Apple Group. Prime Manhattan Realty was integral to our securing a lease for our new 20,010 square foot headquarters at 800 Third Avenue. We appreciate that your team was always available to review thoroughly with us all leasing and acquisition options for our relocation. We also appreciate our continued relationship with Prime Manhattan. Your team has proven to be a great resource for local market knowledge, comparables and new deals.

We have recommended your firm to others for office leasing. We look forward to doing future transactions with your company.Bill, there were two points we relayed to you; the budget and the importance of image. You were successful in achieving satisfaction for both!

Sandy Lewis
Senior Adviser Red Apple Group

more testimonials

Recent Office Lease Transactions

20,000 ft.
Office Space - Lease at 800 Third Avenue
Midtown East
Energy Technologies Firm
18,000 ft.
Loft Office - Lease at 90 Broad
Financial District
Healthcare Tech Firm
12,000 ft.
Office Space - Lease at Empire State Bldg
Technology Patents Law Firm
12,000 ft.
Office Space - Lease at 505 Fifth Avenue
Software Development
10,000 ft.
Office Space - Lease at 712 Fifth Avenue
Hedge Fund
8,214 ft.
Loft Office Condo - Sale - 131 W 33rd
Textiles Showroom
5,800 ft.
Office Space - Lease at 430 Park Avenue
Luxury Intl Home Sales
4,800 ft.
Loft Office - Lease at 24 West
Fashion Internet Sales
3,500 ft.
Office Space - Lease at 445 Park Avenue
Aero Technology Investments
2,700 ft.
Office Space - Lease at 645 Madison Ave
Real Estate Developer
2,500 ft.
Loft Office - Lease at 156 Fifth
Venture Capital Firm

Bill's Office Space Listings

Midtown Office Space Sublet 777 Third Ave.

8,300 SF


Now Offering a Hi-Floor Sublease W/ a USABLE TERRACE & Partial Views of the East River at 777 Third Avenue. Built in 1963, this 628,200 Square Foot Class-A Office Tower stands 38 stories, with incredible windows & views overlooking the East River. If the time has come to search the Midtown NYC office market for your new place of business, secure this beautiful 6-year sublease that is completely move-in ready while it’s still available! Very few spaces actually have the image and build-out that sends a message of success to new clients & new employees.

Office Space For Lease
400 Park Ave

6,000 SF


This Brand New Prebuilt Office Unit is Available For Lease on Park Avenue.
6,000 Square Feet featuring 8 offices, 1 boardroom, 1 conference room, open area suitable for 6 to 12 people.
Move in tomorrow and enjoy 6,000 square feet of built office space in one of Park Avenue’s finest Class-A office towers, where prestige meets functionality. Join the city’s top investment, communications, marketing & legal corporations that have selected this property as their USA headquarters.

Office Space for Lease
77 Water St.

7,300 SF


Enjoy amazing harbor views and an unparalleled skyline, sun-filled days in this Class-A, Financial District building, with brand new pre-built offices located on the 24th floor. The all glass-walled offices and conference rooms in these move-in ready suites offer your hedge fund / investment or software / tech company the comfort and excitement of the most modern office design, creating the perfect branding opportunity for your successful business.

Available Sizes: 7,300 SF / 5,800 SF / 5,300 SF

Office Space Sublet
381 Park Ave. South.

4,340 SF


Take advantage of this FULLY WIRED & FURNISHED SUBLET, ready for your growing business needs! This 4,000 square foot Office Sublease is now Available Immediately For Rent.Loft-style Offices W/ Hi-Exposed Open Ceilings… and Newly Carpeted Floors to keep the noise to a minimum...

Office Space For Lease
295 Madison Ave

6,500 SF


Madison Avenue Grand Central Tower Office Floor Lease / Move-in Ready Loft. Enjoy the breathtaking views of his 30th Flr 6,500 Square Feet Office Space, Available Immediately For Rent within Loft-style Offices w/ Hi-Exposed Open Ceilings & Polished Concrete Floors; Bask in the gleaming sunlight this newly pre-built, high-end design office floor offers!

Third Avenue Manhattan Midtown East Office for Rent

3,800 SF LISTING #WM041118


Best Hi-Floor, Above Standard Office Sublet Deal in Grand Central! This 3,800 Square Feet Office Sublease Being Offered by an NYC Law Firm is now Available. Premier Class-A Offices with all Glass-Walled Offices and plush above standard carpet throughout. Pre-Built Luxurious Offices with a versatile mix of five (5) private furnished offices, a stunning marble floored, open ceiling & fully furnished reception area. Utilize the furnished conference room with AV equipment and get your staff on task right way in six (6) large cubicles that all have high walls for sound diminution. The terrific sit-in Kitchen features all new stainless steel appliances..fridge, microwave & dishwasher are all included.

Spring Street & Broome Street Soho Loft Offices For Rent

1,750 SF LISTING #WM013118


This beautifully appointed, built & move in ready loft office for rent on the 6th floor; the creative layout features 1 large windowed glass-walled executive office, 1 large glass- walled windowed team for 4-6 people, 6-10 cubicles, plus conf area, but even more interesting here are the distinctive, high-end features and finishes used when the space was built...

Available Sizes: 1750 to 6000 SF Now Available

Grand Central Office Space
3rd Ave & 42nd Street

8,500 SFDivisibleNegotiable

This impressive Grand Central office space is one of a kind. Floor to Ceiling windows provide stunning views of New York City and Times Square while providing natural light. The office was recently built and designed to maximize space and offer an ideal working environment. A spacious conference room will impressive your guests as they absorb the views.

Available Sizes: 8,500 SF / 5,500 SF / 3,800 SF/ 1,750 SF

120 West 45th Street Grand Central Midtown West Office Space For Sublease

4,000 SF LISTING #1019


New to Market 4,000 Square Foot Office Sublet Available for Immediate Move-In. This gorgeous glass-walled & sunlight-filled move-in ready office sublet offers you highly impressionable headquarters for your company. Space features incredible views and light! Enjoy incredible views from the 38th floor, and...

23rd Street Flatiron Commercial Loft Rental

11,000 SF LISTING #1018


The 5th floor office is completely move in ready with all high-end finishes. The office space boasts many of the classic charm with cast iron columns, beautiful tin ceiling, oversized arch windows and original oak floors. The charm has been elevated with many contemporary features, for instance, bright track lighting, glass finishes, and modern furniture. The space is a stunning office reflecting the chic Tribeca area with the delicate blending of classic and modern design.

West Broadway Tribeca Commercial Loft Rental

5,000 SF LISTING #1017


The 5,000 SF loft is a rare opportunity to build an office to suit your needs. The office has amazing features with the original tin ceilings, unfinished hardwood floors, and grand columns. Natural light floods the office space with an abundance of windows on the front and rear walls. You can design, customize, and build your office from the white box condition. The vanilla box loft is perfect for a creative, showroom, technology, or media company.

West Broadway Tribeca Commercial Loft Rental

9,000 SF LISTING #1016


This 9,000 SF office features a contemporary design highlighted by the 15ft loft ceilings. Oversized windows frame this office along multiple walls inviting in tons of natural light. The pre-built office contains four glass-enclosed offices, four perimeter offices, two conference rooms, and 50 work stations. This listing is available for immediate lease and occupancy located in the Tribeca neighborhood. The timeless architectural design is perfect for your business and brand.

23rd Street Flatiron Commercial Loft Rental

5,700 SF LISTING #1015


This office space is located on the 8th floor contains 2 windowed offices and a windowed conference room with large operable windows. The large framed windows allow the natural light to flow through the office. The amazing views of Union Square are visible from the offices and conference room. This bright office is delivered with neutral white and brown furniture amplifying the natural light. This neutral decor allows you to move-in and add your touch to the space immediately.

23rd Street Union Square Commercial Loft Rental

4,000 SF LISTING #1014


This office space is located on the 8th floor contains 2 windowed offices and a windowed conference room with large operable windows. The office space on the 8th floor offers a full floor opportunity with lovely natural light. There are two standard offices, a conference room, two private restrooms, and an open bullpen with 20 workstations. The office space is move-in ready with a clean floor plan. immediately.

Fifth Avenue Union Square Office For Lease

3,000 SF LISTING #1013


This office space is located on the 8th floor contains 2 windowed offices and a windowed conference room with large operable windows. The large framed windows allow the natural light to flow through the office. The amazing views of Union Square are visible from the offices and conference room. This bright office is delivered with neutral white and brown furniture amplifying the natural light. This neutral decor allows you to move-in and add your touch to the space immediately.

Columbus Circle Midtown West Condo for Sale

5,600 SF LISTING #1010


This Plug & Play Condo is 5,6000 SF on the 25th floor in Midtown is available for sale. The full floor condominium is atop the European Hotel Flagship in Columbus Circle. The condominium contains 5 pre-built windowed offices with the possibility for more offices. There is a large conference room, open bullpen, eat-in pantry, and private bathrooms.

Penn Station Midtown Commercial Loft Office Space

4,000 SF LISTING #1009


The space offers a small reception area with a waiting room for guests and clients. The office offers an efficient layout with large windows to fill the office with natural light for a bright and open workspace. The space contains 1 standard perimeter office, 2 small perimeter offices, a conference room, and an open bullpen with seating for 25 people. There is also a copy room, data closet, and a pantry. There are 2 private restrooms located within the office space.

Penn Station Midtown Commercial Loft Office Space

3,500 SF LISTING #1008


The office features a small reception area near the entrance to greet clients and guests. 1 standard and 3 small perimeter offices with large windows fill the space with natural light. There is also a mail/copy room, IT closet, and a wet pantry. The open bullpen has space for 15 medium or 20 small workstations.

Broadway Midtown Commercial Loft Office Space

8,000 SF LISTING #1007


This listing is 8,000 SF loft office on the 15th floor in Midtown and is available for immediate lease. The office space is located in the building formerly known as Lefcourt Normandie Building. The building has a beautiful stone facade with large windows boasting the neoclassic design. The prime Midtown location offers great amenities and numerous dining options.

Penn Plaza Midtown West Commercial Office Space Rental

5,000 SF LISTING #1006


This listing is a 5,000 SF Class-A office space on the 20th floor situated in Midtown West. This office is available for immediate sublease. The office is centrally located to excellent entertainment, upscale shopping and restaurants. Hammerstein Ballroom, Madison Square Garden, Macy's, and Keens Steakhouse are some of the amazing neighbors in Midtown West.

Broadway Soho High Floor Commercial Loft Office Space

6,000 SF LISTING #1004


This listing is a 4,500 SF office space on the 28th floor situated in Midtown East is available for immediate lease. This 28th Floor office with large windows offers stunningly gorgeous views of Midtown. Work with the city as your backdrop in 2 Standard perimeter offices and 2 conference rooms. Beautiful glass enclosed offices allow the natural light to flood the space making for a bright and open workspace.

Midtown Manhattan East Midtown Commercial Loft Office Space

4,500 SF LISTING #1003


This listing is a 4,500 SF office space on the 28th floor situated in Midtown East is available for immediate lease. This 28th Floor office with large windows offers stunningly gorgeous views of Midtown. Work with the city as your backdrop in 2 Standard perimeter offices and 2 conference rooms. Beautiful glass enclosed offices allow the natural light to flood the space making for a bright and open workspace.

Bryant Park Midtown Grand Central Office Sublet

5,000 SF LISTING #1002


This space is 5,000 SF office space on the 15th floor located in Grand Central and steps away from Bryant Park. The office is in a commercial building with a beautiful lobby with marble floors and multiple passenger elevators. The pre-built office offers mixed space of 4 standard perimeter offices, 1 large perimeter office, and an open bullpen with 20 workstations.

Fifth Avenue Flatiron Office Space For Rent

4,000 SF LISTING #1001


This listing is 4,000 SF of recently renovated office space on the 9th floor situated in the beautiful Flatiron. Be steps away from the historic Flatiron Building and Madison Square Park! This office is nestled among the beautiful Art Deco architecture of the Flatiron District. Enter into the tastily renovated lobby with boutique floors and upgraded elevators.

Park Avenue Park Avenue Office Rental

5,000 SF


Capture this great below market deal that comes with all the impressive features you could ask for in a luxurious, beautifully built Park Avenue Office. 5000 square-foot office available for immediate sublease, MOVE-IN READY, with furniture, telephones and fixtures! Enjoy the most prestigious office location in the city, Park Avenue, and be surrounded by world-class restaurants, great shopping in the company of the world's leading financial institutions. Enjoy brilliant sunlight in the perimeter offices, further reflected into the space via custom wood and glass lattice office walls.

Available Size: 5,000 SF @ $48/SF

Park Avenue Plaza District Office Space Rental

3,507 SF


The following commercial unit stands within a top quality Class A Office tower situated on the east side of Manhattan near 42nd Street and Lexington. 3507 SF. Available today; empty space ready for occupancy - featuring freshly painted white walls and new charcoal hue carpets - all bound into a great professional space overlooking Lexington. Moreover the office contains a mostly open layout that is serviced by an IT Closet & Pantry (wet column), an austere space with all the bare bones needed; glass fronted entry door, plenty of outlets, some shelf space under the windows, while traditional tile ceilings and fluorescent lighting help finish the space. It should be noted that the landlord will completely build out the space to suit your needs. Previously this unit consisted of a mostly open layout that allowed for a team of 20 to work efficiently and comfortably. In addition to that configuration the office also featured a spacious glass clad conference room, a pantry with room for staff seating, and two restrooms. The building property in which the office stands features a diverse tenant roster that ranges from business consultants to investment financial firms. The available office herein is ready for your customization of the layout - once matched to a qualified business for rental. If interested or simply would just like to know more about the unit, we can provide all the facets from the leasing rate to floor plans; it should be noted that the landlord recently lowered their asking price in keeping with current market dynamics. In summary this space has both the location and quality that top tier professionals are clamoring for.

Central Park South Midtown Office Space in Historic Luxury Building w/ Health Club

6,400 SF


Class-A offices with terraces overlooking Central Park available for lease, this one-of-a-kind luxury office has its own private entrance & elevator, move in ready, ultra high-end trading installation w/ glass features, space is fully wired, with fiber optic line!, unobstructed tree top views facing the park, 3 terraces & conference & full open cafe pantry, 7 offices w/ wood & glass finishes & trading desks, furniture shown is included!

Madison Avenue Midtown Office Space Sublet w/ Exclusive Terrace

10,000 SF


Spectacular Central Park views, rare opportunity new to market, extraordinary landscaped terrace for your exclusive use, in one of the finest Madison Avenue Class A office towers, over the top impressive luxury office installation, all custom glass offices & above standard details & finishes, space seats a staff of 52, 12 offices w/ 20 workstations, plus an open area additional 20 people, and a beautiful above standard pantry.

East 17th Street Union Square Office Space

23,000 SF Negotiable


The 10th and 12th floors are available in this spacious office building on West 17th street and 10th avenue. Each floor consists of over 11,500 sq ft each with 15 windows with amazing views New York City. These offices are newly furnished and have luxurious glass walled offices.

Available Sizes: 23,000 SF / 16,000 SF / 11,500 SF / 8,000 SF

East 24th Street Park Avenue South Work/Live Loft

4,800 SF Divisible Negotiable


This open commercial loft space features 12' ceilings and beautiful wood floors. The space is on the ninth floorwith three sides of large double paned windows; offering fabulous views and good natural light. This loft has a low loss factor at only 18% with Private Acess direct to the space. This work/live space comes with two kitchens, two bathrooms, and two passenger eleveators and one freight. The building boosts a beautiful lobby offering 24/7 access.

Available Sizes: 23,000 SF / 16,000 SF / 11,500 SF / 8,000 SF

Broadway Grand Central Office Space

6,800 SF Divisible Negotiable


This 7,000 SF space can be subdivided into a 4000 SF space as well as a 2800 SF space. This office has boasts a bright space with windowed offices as well as cubicles. It has a raised floor server room, state of the art conference room, and a pantry. It is one of the best locations in Times Square.

Available Sizes: 6,800 SF / 4,000 SF / 2,800 SF

Fifth Avenue & 57th Street Midtown Office Space

9,900 SF Divisible Negotiable


Ready to move in sublet with 9 windowed offices, 18 workstations, pantry, and a conference room. High ceilings, wood floors, and video intercom. Furniture available. Open layout has a full kitchen, 1.5 baths, and flexible living area. The loft is wired for high-speed internet access and was recently up graded with new windows, new electric, and new HVAC unit.

23rd Street
Fifth Avenue Office Rental

4,000 SF


Pre-Built Space / New Renovation - This listing is 4,000 SF of recently renovated office space on the 9th floor with elevators that open directly (via keyed access) onto the space which is all situated in the beautiful Flatiron District right off of 23rd Street and Fifth Avenue in Manhattan. This pre-built commercial unit has been built with a layout which includes an open bullpen that can fit 10 workstations, 1 small internal private office and 3 perimeter private offices all outfitted with large operable double-slung windows. This contemporary renovation also features reclaimed dark stained hardwood floors that are accentuated by the use of glass doors and trim which work together to blending the whole into an inviting modern workplace. The office listed herein stands on the 9th floor of a well managed 14-story midtown commercial building - with unobstructed views looking southward as detailed in the photos.

Available Sizes: 4,000 SF

Park Avenue and 55th Street
Park Avenue Office Space

7,100 SFDivisible, Negotiable

Move your small business to this trendy Soho commercial loft. Located in the heart of Soho, on Spring Street and Broadway, this New York office space is in the prime location for any growing business. Not only is the location a great benefit of this space, but also the quality of the loft is astounding.

Available Sizes: 7,100 SF / 4,000 SF / 3,100 SF

Times Square Office Space
40th Street Bryant Park

7,500 SFDivisibleNegotiable

There are 7,500 sq ft available and this can be broken down to as little as 2,500 sq ft depending on your preferences. The space is freshly re-finished with 14ft ceilings and a very impressive reception area that welcomes visitors and employees to your full floor loft office space. The landlord is willing to completely customize the space to meet your exact specifications!

Available Sizes: 7,500 SF / 5,000 SF / 2,500 SF

Fifth Avenue & 20th Street Flatiron Full Penthouse Floor Office Space Direct Lease

9,000 SF Divisible Negotiable


This pre-built space features 20ft ceilings with 10 offices, conference, 3 bathrooms & pantry area. Incredible views with four sides of windows! Supplemental airconditioning in server room. Below market commercial space for lease. The landlord was asking $60/SF originally, now the price has been REDUCED! Landlord will modify layout per request.

Available Sizes: 9,000 SF / 6,000 SF / 3,000 SF

551 Madison Avenue East Midtown Manhattan Office Space

3,428 SF Divisible Negotiable


This move-in ready Class-A Sublet on Madison Avenue in the upscale Midtown East Office District comes fully furnished & completely wired for telephone and computers. Madison Avenue & 55th Street is one block east of Manhattan's Fifth Avenue luxury shopping area, and two blocks south of the world famous shops of 57th Street. The finishes in this sublet include the latest modern basket lighting fixtures, smooth finish ceiling tiles, floor-to-ceiling perimeter windows in and glass panels on all six private offices; turn-key office space that will save you both time & money.

East Midtown Office Space
Madison Avenue

6,000 SFDivisibleNegotiable

Tenant wishes to sublease an approximate 6000 ft. portion of their space. Above Standard Installation w/2 Conference rooms + Law Library. Perfect Madison Avenue address for Law or Accounting firm, with 8 Perimeter offices, 4-5 Secretarial Stations - This Office is Move In Ready!

Available Sizes: 6,000 SF / 2,650 SF / 1,900 SF

Madison Avenue 6th Floor Grand Central Office Space

6,200 SF Divisible Negotiable


This is one of the most prestigious office spaces we have. Located on a major avenue, Madison Avenue, two blocks away from Grand Central, one block adjacent to Fifth Avenue Library & Bryant Park, this is the dream location for every business in Manhattan. Transportation is very convenient, the building is near major subway and bus lines.

Available Sizes: 6,200 SF / 3,200 SF / 3,000 SF

Grand Central Office Space
42nd Street & Park Avenue

6,900 SFDivisibleNegotiable

This commercial space is in excellent condition. It is fully furnished, phones and high speed internet are already installed. You could move in immediately!! The space is pretty spacious, 6,900 sf and has got perimeter offices. There are exceptional views towards Grand Central Station. This is an impressive and beautiful area.

Available Sizes: 6,900 SF

Grand Central Office Space
Madison Ave & 44th Street

6,500 SFDivisibleNegotiable

This 6,500 sq. ft. office space has a perimeter office layout with many windows. This office would be great for a law, accounting, or insurance firm. This office comes pre-built with 14 windowed offices, 3 interior offices, secretarial support areas, a board room, and a pantry.

Available Sizes: 6,500 SF

Eighth Avenue Meatpacking District Office Space

3,000 SF Divisible Negotiable


This full floor commercial loft is located in Chelsea/Meatpacking District has what one would expect. High exposed ceilings with floor to ceiling wrap around windows in two corner offices. The space enjoys new bamboo hardwood floors, plus above standard pendant lighting fixtures. The loft is flexible in that its built with many windowed offices & open areas which give the workspace balance. This loft comes fully wired and move-in ready.

Park Avenue Grand Central Office Space

5,600 SF Divisible Negotiable


This commercial real estate property consists of 10 windowed offices and 3 corner offices. Each office is prewired for telephone and data services. This office space also hosts renovated private restrooms, a kitchen area, and a spacious kitchen. This office provides all the essentials for you and your staff, and is an ideal work environment.

Available Sizes: 5,600 SF / 4,000 SF / 3,000 SF / 2,000 SF