ST. LOUIS — JAB Holdings, the owner of Caribou Coffee and Krispy Kreme Doughnuts, said on Wednesday it would buy bakery chain Panera Bread Co. for $7.5 billion, as it expands its coffee and breakfast empire through one of the biggest-ever U.S. restaurant deal.

JAB, the investment vehicle of Germany’s billionaire Reimann family, has built an empire of coffee and food chains through a series of acquisitions in recent years, including that of K-cup coffee pod-maker Keurig Green Mountain Inc.

Panera has about 2,000 bakery cafes in the United States, and its fresh offerings appeal to health-conscious consumers.

Shares of St. Louis-based Panera jumped 14.2 percent to a record high of $312.94 on Wednesday. JAB offered $315 a share in cash, a 20.3 percent premium to the stock’s closing price on March 31, the last trading day before media reports of a potential deal.

“We view the acquisition as strategically compelling for JAB ... we view the acquisition price as high enough to preclude a competing financial suitor,” Wedbush Securities analyst Nick Setyan said in a note. He said JAB’s offer was largely in-line with multiples it has paid for other acquisitions, including Peet’s Coffee & Tea and Caribou Coffee.

The acquisition of Panera will be North America’s second-biggest restaurant deal after Burger King’s $11.53 billion purchase of Canadian chain Tim Hortons, according to S&P Global Market Intelligence.

Panera has reported better-than-expected earnings per share for six quarters. On Wednesday, it reported preliminary first-quarter company-owned sales-store growth of 5.3 percent, which Mr. Setyan said comfortably beat Wall Street’s expectations. 

JAB will assume about $340 million of Panera’s net debt, valuing the deal at $7.5 billion, the firms said in a joint statement. They expect the deal to close in the third quarter.

First Published April 6, 2017, 4:00 a.m.