NEW YORK - While the focus at General Motors Co. in the past several months has been on the change to new marketing chief Joel Ewanick, on reshaping Chevrolet and Cadillac and on the automaker's impending initial public offering, very quietly the Buick brand has become a driving force for the company, Automotive News reported.

A new design and a marketing shift targeting a younger audience have helped U.S. sales of Buick's Enclave, Regal and LaCrosse skyrocket since last year -- and even more so in China, where it is the No. 1 brand.

To steal a line from the classic Oldsmobile campaign, this is not your (grand)father's car any more.

That campaign didn't increase sales of Oldsmobiles that much, and it remains to be seen whether the Buick surge can be sustained. But Ewanick is confident that the brand is back.

"Buick is just nothing but blue sky," he said. "It's the fastest-growing brand in America, and we're selling LaCrosse as fast as we can get them. It's a great success story."

After 25 years of falling sales, GM sold 137 percent more Buicks in July than it did in July 2009. Through the first seven months of this year, sales are up 60 percent over the same period last year. GM is on track to sell more than 148,000 Buicks in the United States this year, up from 102,306 last year and 137,197 in 2008.

How did Buick's sales rebound? And how has the brand stuck -- fairly or unfairly -- with the tag of being a "senior citizen's car" turned its fortunes around?

"It's a change in design that appeals to younger people," said Charles Krome, a writer and analyst for Autotropolis.com. "It's much more up to date and comparable to what's out there on the market. And GM is really making an effort to get past that whole 'grandfatherly' car thing with the marketing to younger customers."

Last year GM decided to end its relationship with golfer Tiger Woods (before his much-publicized personal problems) and to stop sponsoring the Buick Open. The flailing economy was blamed as well as GM's subsequent need for a $50 billion government bailout. But it was also a calculated move because the golf community tends to skew old.

GM is positioning Buick as a luxury brand -- often comparing it to Lexus and Acura -- and reaching out to younger buyers while maintaining an Average Joe pricing structure. The average age of a Buick buyer has dropped to 61 from 64 in the past 18 months, according to autoguide.com. That's still high compared with the average mid-50s buyer for Lexus and Acura, but it shows Buick's commitment to marketing to a younger audience.

Buick also has embraced social media. In June, GM launched a Web site, momentoftruth.com, in which it invites comments about the 2011 Buick Regal -- good, bad or indifferent.

One woman wrote, "Isn't Buick Regal just a car for Jersey-ites in their 80s?" while another wrote on Buick's Facebook page, "A definate [sic] American eyebrow raiser that says HMMMMM!!! I Love It!!"

The company also has hosted get-together parties in several cities and handed out Flip video cameras for attendees to record their thoughts on the car. The videos are then posted to the site.

"Straightforward advertising is what they had been doing, letting the car be the hero, talking about the features, letting people see the styling," Ewanick said. "What we need to do in quick order is to start to frame and define what that brand is going to stand for. We're working on that right now."

GM is exploring whether to expand the Buick lineup to six or seven models -- including a hybrid version of the LaCrosse sedan, a baby crossover and a compact sedan. The Lucerne sedan will be dropped after the 2011 model year.