Wilmer Cutler Pickering Hale and Dorr has started its first management transition since a 2004 merger of Washington, D.C.-based Wilmer Cutler and Boston-based Hale and Dorr established the 1000-lawyer firm.

On Monday, Wilmer announced that partners Susan Murley and Robert Novick will assume the roles of co-managing partners on January 1, 2012. Murley chairs the firm’s transactional practice; Novick chairs the firm’s regulatory and government affairs practice. Murley and Novick succeed partners William Perlstein and William Lee. The two current co-managing partners orchestrated the 2004 merger.