Starbucks Corp. will close 600 coffee shops in America and eliminate as many as 12,000 jobs, the most in its history, as the company’s chief executive officer, Howard Schultz, slows the chain’s expansion after it doubled in size in four years.

Starbucks gained as much as 7.2% in late Nasdaq trading after saying the reductions amount to 7% of its workforce worldwide. The cuts include full- and part-time employees and will come over the next nine months, the Seattle-based company said yesterday in a regulatory filing.

Seventy percent of the stores to be shut are less than three years old, the company said. Mr. Schultz, the 54-year-old former CEO who regained the post in January, is coming to grips with Starbucks’ declining earnings and the “overgrowth” of the past few years, an analyst at Oppenheimer & Co., Matthew DiFrisco, said.

“It shows Schultz is willing to do the tough things that are necessary,” an analyst at Coldstream Capital Management Inc. in Bellevue, Wash., James Walsh, said yesterday in a telephone interview. Coldstream has $1.1 billion under management, including Starbucks shares.

The chief financial officer of Starbucks, Peter Bocian, estimated the stores were taking 25% to 30% of sales from nearby locations. The closings will hurt long-term revenue projections while helping the company achieve its profit goals, Mr. Bocian said on a conference call, without elaborating.