Herrick Feinstein, founded as a real estate boutique in Manhattan nearly 90 years ago, has bolstered its core practice by hiring Cleary Gottlieb Steen & Hamilton senior attorney Patrick O'Sullivan as a partner.

“Given Herrick's position in the market as one of the leading law firms, particularly as it comes to New York real estate, was just another added bonus and a very attractive piece of why I wanted to join the firm,” O'Sullivan said Monday. “I feel that strength at a more local level really works well with what my focus is in terms of public-private development particularly as it relates to projects in and around the New York City area.”

O'Sullivan began his legal career in 2001 as an associate at Shearman & Sterling, where he remained for more than five years before taking a position as an executive vice president at the New York City Economic Development Corp. in 2007.

In that role, O'Sullivan worked with real estate developers and governmental agencies on many public-private transactions in the city. O'Sullivan led the city's efforts to acquire Brooklyn Bridge Park and Governors Island from New York state and oversaw negotiations for the development of two sites near Brooklyn Bridge Park.

He also directed New York's negotiations for the development of New York University's Center for Urban Science and Progress in Brooklyn, the redevelopment of South Street Seaport's Pier 17 by the Howard Hughes Corp., Staten Island's new Empire Outlets; and the now “indefinitely delayed” nearby New York Wheel. (Herrick also had a role advising a consortium on the South Street Seaport project, as well as Staten Island's adjoining development sites.)

In 2014, O'Sullivan returned to private practice as senior attorney at Cleary Gottlieb, where he advised clients on a variety of real estate developments and transactions, particularly those arising from public-private partnerships, a subject he has previously written about for the New York Law Journal.

Herrick's depth in these types of transactions and the opportunity to work with its well-regarded real estate group helped draw O'Sullivan to the firm. So did a land use team helmed by partner Mitchell Korbey, as well as a government relations group co-chaired by former U.S. congresswoman Elizabeth Holtzman. (Michael McMahon, a former New York congressman hired by Herrick in 2011 to co-chair its government relations group, left the firm in late 2015 after being elected district attorney for Staten Island.)

O'Sullivan said his ability to assist clients on complex public-private development transactions will be enhanced at Herrick, which has the capacity to “counsel them from beginning to end” on such deals, he said. O'Sullivan is the most recent addition to the firm this year, though the firm has seen its share of departures.

Nancy Mertzel, the former head of Herrick's intellectual property group, left the firm this summer to start her own boutique. In March, Herrick lost longtime partner Christopher Sullivan, a former co-chair of its litigation group and a member of its executive committee, to Mintz, Levin, Cohn, Ferris, Glovsky and Popeo in New York. Three months later, Therese Doherty, the head of Herrick's securities, futures and derivatives litigation practice, joined Sullivan at the firm.