• by Sarah Mahoney  @mahoney_sarah, July 31, 2007

Gap Inc.--struggling to reverse a persistent slide in its U.S. stores--has launched a new ad campaign, using celebrity portraits shot by Annie Leibovitz.

Themed "Classics redefined," the company says the new ads play up Gap's commitment to personal style.

"Fashion portraiture is a subject near and dear to Gap. Our advertising has always put the individual ahead of the clothes," the company says in its announcement. "Whether it's a celebrity, a writer, a performing artist or a model, the person is always the art, the clothes the frame that sets them off. And a compelling portrait is a way to make sure it lives on forever."

Ads, running in September magazines, focus on such A-list celebrities as musician John Mayer and actors Forest Whitaker and Lucy Liu, as well as quirkier selections, like comedian Sarah Silverman and choreographer Twyla Tharp. Each of the 12 portraits focus on a wardrobe staple, and Gap is hoping the new effort will spark sales as it heads into the critical fourth quarter.

But the company continues to struggle. Gap, which named Glenn Murphy as its new chairman and CEO last week after months of speculation, has been struggling with poor sales and an exodus of talent.

Earlier this month, it announced that its June sales fell 4% overall, with same-store sales at its North American Gap stores plunging 9%, and sales at its Old Navy division skittered 6%. Same-store sales at Banana Republic North America gained 6%.