Following months of speculation about where Chadbourne & Parke would move its New York office once its current lease expires, the firm announced Thursday that it has agreed to take over a portion of the space previously occupied by Dewey & LeBoeuf at 1301 Avenue of the Americas in midtown Manhattan.

Chadbourne signed a 20-year lease and will move into the new space “once the demolition, redesign, and build-out of its new offices are finished,” according to a press release. The move will be a short one given that the firm’s New York office is currently located around the corner at 30 Rockefeller Plaza. As The Am Law Daily previously reported, Chadbourne’s current lease is set to expire in 2014, and accounting firm Deloitte is already set to take over the floors the firm currently inhabits.

In its new building, Chadbourne will initially take up more than 200,000 square feet on six floors, as well as concourse and subconcourse space, with options to renew or expand built into the lease. That still leaves a number of vacant floors in the building, which is owned by Paramount Group Inc. Dewey occupied roughly 500,000 square feet spread across more than a dozen floors in the 45-story building, according to our past reports, with a lease due to expire in 2020. Ted Koltis, senior vice president of leasing for Paramount, declined to comment Thursday.

In June, Dewey urged the bankruptcy judge overseeing its case to allow it to reject leases covering 14 domestic and nine international offices, including the firm’s lease on the Avenue of the Americas space. That request was granted July 26. Dewey’s chief restructuring officer, Joff Mitchell, had no comment Thursday on what Chadbourne’s move means for the Dewey estate. (At the time of Dewey’s May 28 bankruptcy filing, Paramount was listed as one of the firm’s largest unsecured creditors, owed $3.8 million for property taxes and May rent.)

No one from Chadbourne was immediately available for comment Thursday. Real estate partner Richard Sonkin led an internal team on the search and negotiation of the new lease, with real estate firm Newmark Grubb Knight Frank also advising. In a statement, Chadbourne managing partner Andrew Giaccia said the firm plans to “create a state-of-the-art workspace for our clients, our lawyers, and our staff.”

Earlier this year, rumors spread that the firm was close to signing on at the unfinished tower at One World Trade Center, and later at 11 Times Square and 250 West 55th Street. The New York Observer first reported July 20 that Chadbourne was headed to the former Dewey space.

Chadbourne’s New York headquarters is currently the largest of the firm’s 12 offices, housing roughly half of its 400 lawyers. Over the past two years, Chadbourne has expanded into São Paulo and Istanbul. During that time, a handful of firms have raided Chadbourne for their own office openings, including Dechert, which poached Chadbourne’s entire 11-attorney team in April to open in Almaty, Kazakhstan, and Herbert Smith, which grabbed six tobacco litigation partners in New York and London to reestablish a presence in the United States.

Elsewhere in Manhattan, Sedgwick is moving October 15 to Two World Financial Center, where it will occupy the 28th floor on a 12-year lease. Sedgwick has been in New York for 27 years and is currently located at 125 Broad Street.

Earlier this summer, The Am Law Daily took a look at a number of other lease signings and office openings, including Wilmer Cutler Pickering Hale and Dorr‘s move to brand-new space at 7 World Trade Center.