UPDATED: 2/4/14 3:20 pm ET - adds link
DETROIT -- General Motors appointed Buick-GMC sales chief Brian Sweeney to Chevrolet's top U.S. post, part of an effort by GM's biggest brand to boost its sliding market share.
Sweeney, 46, will become U.S. vice president of Chevrolet, in charge of sales, service and marketing, GM said in a statement. He replaces Don Johnson, 56, who will retire.
Succeeding Sweeney as U.S. vice president of Buick-GMC is Duncan Aldred, 43, chairman and managing director of GM's Vauxhall Motors brand in the United Kingdom.
The changes take effect March 1.
The moves come one month after GM appointed Steve Hill as its new head of U.S. sales, overseeing both Chevy and Buick-GMC. He succeeded Alan Batey, who was promoted to president of GM North America.
Sweeney and Aldred will report to Hill.
"Brian and Duncan both have a broad understanding of sales and marketing and the right skills to help us delight our current customers and attract new ones," Hill said in a statement.
Johnson had been head of Chevy sales and service since June 2012. Before that he was vice president of U.S. sales operations.
"Don has contributed to GM's success in markets around the world, and we wish him and his family well as he concludes his GM career," said Batey, who also is president of global Chevrolet.
Chevrolet's U.S. market share slipped to 12.5 percent last year, from 12.8 percent in 2012 and 13.9 percent in 2011. In January, Chevy's sales slid 13 percent, dragging its market share down to 11.8 percent for the month, vs. 13.2 percent a year earlier.
Despite the shrinking share, GM executives have touted the brand's sharply higher transaction prices on its rejuvenated passenger car lineup and its redesigned Silverado pickup.
Sweeney has been head of sales for Buick-GMC since March 2010. He's generally well-liked by dealers, who credit him with boosting Buick's lease business and raising customer-service standards, including the implementation of a courtesy transportation program for service customers.
Mike Bowsher, who owns four Chevy and Buick-GMC stores in the U.S. Southeast and was chairman of Buick-GMC's National Dealer Council until January, says Sweeney seeks input from dealers on big initiatives.
"He knows how to set a goal and make sure that everyone understands how to execute it," Bowsher says. "And he's always on. You can call him at 5:30 in the morning or 9:30 at night. He's going after the business all the time."
Sam Slaughter, dealer principal of Sellers Buick-GMC in suburban Detroit, credits Sweeney for setting a vision for Buick and GMC after GM's 2009 bankruptcy, when the fate of both brands was uncertain.
"He's a car guy," Slaughter said. "He understands product and how you sell it and what happens in the showroom."
Chevrolet's U.S. sales have declined two consecutive months, with volume off 8 percent in December and 13 percent last month.
Still, GM executives believe the brand has strong momentum in the market, and point to the Corvette and Silverado winning North American Car and Truck of the Year awards at the 2014 Detroit auto show in January. It was the first time GM had swept the awards since 2007.
Overall, U.S. sales of Chevrolet rose 5 percent to 1.95 million last year while Buick deliveries increased 14 percent to 205,509, and GMC gained 9 percent to 450,901.
Sweeney joined GM in 1990 and has worked in sales and service jobs at Pontiac and Saab.
Aldred also joined GM in 1990, at Vauxhall's Ellesmere Port plant. He worked in various sales and marketing positions at Vauxhall before being named managing director in 2010. He added the chairman title in 2011 and last year was also named acting vice president of sales, marketing and aftersales for Opel/Vauxhall.
Sean Gagnier contributed to this report.
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