General Motors said it moved its Chevrolet Silverado ad account from Publicis Groupe's Leo Burnett to Interpublic's Commonwealth.
In a statement, GM said it made the move "in an effort to streamline business and ensure consistency." Leo Burnett will continue to handle GM's Buick and GMC accounts.
Leo Burnett executives told employees about the move in a memo on Wednesday.
"The outcome for us is unfortunate. We're losing Silverado but keeping the rest of our healthy GM portfolio," the memo said.
"The client has assured us that this isn't a reflection of the team or the work. We are both so proud of how you delivered big, brand-building ideas that really made a difference."
Commonwealth is the advertising shop created in March 2012 as a joint venture between Omnicom's Goodby Silverstein & Partners and Interpublic Group of Cos. McCann, to handle Chevrolet. Goodby later split from the venture.
GM moved the Silverado account to Burnett in 2012, partly to alleviate Commonwealth's workload as it geared up to handle work for more than 20 vehicles in 2013, the company said at the time.
"We’ve been very pleased with the work from Leo Burnett and wish them well as they continue their focus on GMC and Buick," GM's statement said.
Silverado's U.S. sales rose 10 percent in 2014 to 529,755 vehicles. Sales rose 24 percent over the first two months this year to 81,501 units.
Ian Jones, exec vice president and group account director at Leo Burnett Detroit, and Rich Stoddart, North American CEO, sent the memo.
Automotive News contributed to this report.