Starbucks Corp. baristas voted to unionize at a third company cafe, as the chain has intensified efforts to win over employees who have held pro-union rallies.

The 25-3 vote tally in favor of forming a union at a cafe in Mesa, Ariz., took place Friday afternoon, after the main U.S. labor relations body struck down the coffee company’s request to reconsider whether it was appropriate for individual stores to vote to organize.