Wendy’s shares jumped more than 14% Wednesday after noted investor Nelson Peltz made an offer to buy the chain, which has been struggling with high beef prices and aging stores.

Peltz’s Trian Fund Management and several partners are offering Wendy’s $7.35 per share in cash, or a premium of nearly 19% over the stock’s closing price on Tuesday, in a deal that would take the company private.

Wendy’s, which is based in Dublin, Ohio, confirmed receipt of the unsolicited proposal in a statement Wednesday and said its board has formed an independent committee to evaluate it. At the end of last year, Wendy’s had 5,969 restaurants in the U.S. and 1,428 outlets in 38 countries.

Wendy’s, founded in 1969 by Dave Thomas and named after his daughter, is known for its square burgers and Frosty desserts. The fast-growing chain introduced the drive-thru window in 1970 and went public in 1976. In the 1980s, as it jockeyed for sales with McDonald’s and Burger King, Wendy’s launched salad bars and ran its iconic “Where’s the beef?” ad campaign.

But as the fast-food market grew even more competitive and rival burger-focused chains like In-N-Out and Five Guys expanded, Wendy’s fell behind. Wendy’s share of U.S. burger chain sales fell from 11.5% in 2019 to 10.4% last year, according to Technomic, a market research company.