Mullen's Winston-Salem, N.C., office bested Publicis Groupe's Publicis & Hal Riney, San Francisco.
Riney had been the agency for First Union, while Mullen handled the Wachovia account. The two shops had a shootout to determine which would be the agency of record.
The loss is the second major hit taken by Riney, which earlier this year failed to keep General Motors Corp.'s $300 million Saturn Corp. account. Riney's key remaining client is Sprint PCS.
Executives at Riley did not return calls seeking comment.