Starcom beat Publicis Groupe's Zenith Media in a final shootout for the account.
The review began in May
Carat dropped out due to a conflict with a newly won client, Bank One.
Final pitches were heard last week, with agencies dropping one by one until only Starcom and Zenith remained standing, according to executives in the review.
The review included a controversial online reverse auction in which competing shops posted their cost estimates on a Web site in real time and were able to view rival bids for the business -- and also undercut them.
Calls to the Bank of America and Starcom were not returned at press time.