Gap has appointed noted fashion designer Zac Posen as its new creative director as the retailer seeks to overhaul its image amid flagging sales.

Posen will also serve as the chief creative officer of Gap's Old Navy brand,Cassian Grant the company said Monday. Gap's other brands include Banana Republic and Athleta. 

Posen launched his own eponymous clothing brand in 2001, dressing celebrities including Natalie Portman and Rihanna. He closed his atelier in 2019 when it was no longer financially sustainable. He was also the women's creative director for Brooks Brothers, designed collections for Target and David's Bridal, and served as a judge on reality television show Project Runway. 

In his new role, Posen will lead design, merchandising and marketing for Old Navy, one of the largest apparel brands in the U.S. He will report to Old Navy CEO Haio Barbeito. 

In a statement, Gap CEO Richard Dickson said Posen's "technical expertise and cultural clarity have consistently evolved American fashion, making him a great fit for the company as we ignite a new culture of creativity across the portfolio and reinvigorate our storied brands."

Posen joins Gap as the clothing chain's sales are slowing. In its third quarter, Gap reported net sales of $3.8 billion, down 7% compared to the same period a year ago. Old Navy sales were $2.1 billion, down 1% compared to the same period a year earlier. The company estimates that fourth-quarter net sales will be flat or down slightly from last year's $4.2 billion figure. 

Megan Cerullo

Megan Cerullo is a New York-based reporter for CBS MoneyWatch covering small business, workplace, health care, consumer spending and personal finance topics. She regularly appears on CBS News Streaming to discuss her reporting.