Over 30 Years of NYC Office Leasing Success. Founded in 1988, NYC Office Suites is the leader in Class A Executive Office Suites in the New York City and Metropolitan area. With locations in some of NYC’s best buildings they offer unparalleled service with a prestigious address. They have locations at Rockefeller Center, CitiCorp Building, the Plaza District and Grand Central. Their Grand Central location has direct access to all metro north and subways. Whether it is the Metro North or LIRR, their clients will never have to go outside during inclement weather. NYCOS is a Blackfield owned company.