SEATTLE – Starbucks Corp. said Tuesday it will close 600 company-operated stores in the next year, up dramatically from its previous plan for 100 closures, a sign the coffee shop operator is still feeling the pain from the faltering U.S. economy.

Starbucks said in a statement that 70 percent of the stores to be closed were opened after the start of 2006. The locations set to close include ones that “were not profitable and not projected to provide acceptable returns in the foreseeable future,” it said.

About 12,000 workers will be affected by the closings, which are expected to take place over the next year, according to Valerie O’Neill, a spokeswoman for the company.

O’Neill said most of the employees will be moved to nearby stores, but she did not know exactly how many jobs will be lost.