By Nate Raymond

(Reuters) - More than 50 lawyers from Dewey & LeBoeuf, the ailing U.S. law firm on the verge of closure, jumped ship to rival Greenberg Traurig on Monday.

The defections, which include the bulk of Dewey's Warsaw office and at least two partners from its London office, come weeks after Greenberg confirmed that it had ended talks with the troubled law firm about a large acquisition.

"We are working closely with clients on a seamless transition," Lejb Fogelman, one of the Dewey partners in Warsaw joining Greenberg, said in a statement.

Also on Monday, Jones Day announced that it would hire four bankruptcy partners in Los Angeles from Dewey, including Bruce Bennett, who represented the Los Angeles Dodgers in the team's Chapter 11 bankruptcy filing.

Once one of the largest law firms in the United States, Dewey has lost more than two-thirds of its roughly 300 partners to other firms amid concerns about compensation and a heavy debt load.

Dewey on May 4 warned employees of mass layoffs and of the possibility the firm may shut down.

The firm has laid off 433 employees in New York, according to a legal notice published by the New York State Department of Labor. The notice lists Tuesday as the date of a "conditional plant closing."

Mike Sitrick, a spokesman for Dewey, did not respond to a request for comment.

In mid-April, 1,800-attorney Greenberg confirmed that it had "preliminary discussions" with Dewey about a possible acquisition. Those talks came to an end after Dewey told partners that its former chairman, Steven Davis, was the subject of a criminal probe. Davis has denied any wrongdoing.

The Warsaw office will operate as Greenberg Traurig Grzesiak, named after Dewey's former Warsaw managing partner, Jaroslaw Grzesiak. Other partners joining Greenberg Traurig in Warsaw include Fogelman.

Frank Adams, a former Dewey executive committee member and chair of its corporate finance practice, will join Greenberg in London and New York.

(Reporting by Nate Raymond; Editing by Noeleen Walder and Steve Orlosky)