This is the third major agency shift for the auto giant since early 2006.
Good news for Burnett
The move is a coup for Burnett, whose Detroit-area office lost GM's national Cadillac account a little over a year ago without a review when the automaker shifted it to Modernista, Boston. The Burnett office remains Pontiac's national creative agency of record.
A Burnett subsidiary shares the regional dealer work for GM's Pontiac-Buick-GMC division with a McCann unit in a joint venture.
McCann lost GM's corporate-reputation account after a six-year run without a review last fall to sibling Deutsch, Los Angeles.
Executives from McCann and Burnett did not return calls, and a GM spokeswoman said she was unable to comment.
Attracting younger buyers
Buick has struggled in the past decade to attract younger buyers. Although its model lineup is in the process of being trimmed, its freshest models have been getting some kudos.
The brand has changed ad messaging three times in the past three years. Last month, Buick introduced the ad tagline "Drive Beautiful" for the launch of the new Enclave crossover in work from McCann.
Buick has also had some changes at the top. John Larson, general manager of the Pontiac-Buick-GMC division, left the automaker in May to head a radar-detector maker. His successor is Jim Bunnell.