Chadbourne & Parke’s longtime managing partner Charles O’Neill is stepping down to be replaced by Andrew Giaccia, the firm’s executive partner and managing partner of the Washington, D.C., office. Mr. Giaccia, 51, takes over today as managing partner of the 457-lawyer firm and will relocate to New York. Mr. O’Neill, who had been the managing partner since 1998, will remain a partner and focus on continuing the firm’s expansion and development of international offices.

The management election took place before Thanksgiving and was uncontested, said Mr. Giaccia, who will also take Mr. O’Neill’s place on the five-person management committee. Mr. Giaccia, who also headed the firm’s environmental practice, said the firm would continue in the same “successful direction” as before.