BUFFALO, N.Y. -- Employees at three more Starbucks stores in suburban Buffalo have voted to form unions, a count of ballots revealed Wednesday, bringing to six the number of unionized Starbucks shops and further advancing organizing efforts underway in at least two dozen states.

       Workers at stores in Cheektowaga, Amherst and Depew voted by narrow margins in favor of unionizing, according to the National Labor Relations Board's tally. The count was 8-7 in Cheektowaga, 15-12 in Amherst and 15-12 in Depew.

       The vote count was delayed for two weeks after Starbucks filed a request for review with the labor board. The Seattle-based coffee giant argued that its Buffalo-area stores should vote as a group on the issue of unionization, rather than individually, to avoid labor instability across stores that may share employees. The NLRB on Monday ruled against the request, saying it saw no issues.

       The company has actively fought unionization, saying its more than 8,000 company-owned U.S. stores function best when Starbucks works directly with employees, which the company calls “partners.”

       It was the second round of union votes involving Starbucks stores in Buffalo, where the spreading efforts to unionize first took hold. Two stores voted in favor of unionizing in December. A suburban Phoenix location last month became the first store outside New York to organize.

       They are the first Starbucks-owned stores in the U.S. to be represented by a union since the 1980s when the United Food and Commercial Workers union represented workers at six stores in the Seattle area for several years.

       Employees who favor unionizing say they want more input, through collective bargaining, on pay, working conditions and store operations.

       Workers at more than 100 stores in 26 states have now petitioned the NLRB to hold their own union elections, according to Workers United, the union that's organizing the effort.

       Union membership levels are rising for U.S. workers between 25 and 34 years old, even as they decline among other age groups, according to the federal Bureau of Labor Statistics.