Teamster truckers and warehouse workers who supply food, coffee and paper goods to 900 Starbucks stores in Minnesota and three other states are still working to negotiate an extension to a labor contract that expired months ago, union officials said.

However, any food shortages at stores are unrelated to the labor dispute, union and Starbucks officials said.

Some 300 Teamsters Local 710 members voted last month to authorize a strike against DPI Specialty Foods. But to date no strike actions have taken place and contract talks continue, Teamsters officials said Tuesday.

While some customers in the Twin Cities have cited a shortage of food products, spokesman Erik Moser said Starbucks was not aware of any allocation problems in Minnesota. Food shortages in Starbucks stores in the Chicago area had generated headlines, but officials said the labor dispute and the food supplies were two separate issues. DPI has not missed deliveries, Moser said.

Moser acknowledged there were some supply "allocation" problems in Illinois that had left some Starbucks stores with too much of one product and not enough of another. "Now that has equaled out," he said, adding that the "allocation issue was quickly cleared up in Chicago."

The labor contract in question covers about 300 DPI truck drivers and warehouse workers who supply Starbucks in the metro areas around Chicago, Minneapolis, St. Louis and Indianapolis. About eight to 10 DPI drivers based in Minnesota are affected by the contract talks, union officials said.

DPI officials in Minneapolis and Chicago did not return phone calls seeking comment.

Teamsters Local 710 Secretary Mike Cales said in a statement that his DPI workers usually get a multiyear labor contract, but the company now wants a seven-month instead of a five-year term.

"This extremely short contract is one of the reasons why our members voted it down," he said.

Starbucks is not involved in DPI's labor discussions, Moser said. But he noted that Starbucks intends to replace DPI with an "alternative provider" soon because DPI lacks "the capacity and infrastructure to adequately support Starbucks' growth in the market."

Moser declined to elaborate on how Starbucks is growing or why DPI could not continue to meet its needs. He said Starbucks and DPI had been in talks for the past year.

Cales said the union understands that Starbucks might be looking to replace DPI with another vendor. But he still hopes that Starbucks will help secure the jobs of workers who delivered goods to Starbucks stores for years.

"Local 710 Teamsters who have loyally served Starbucks will be calling on the company to do the right thing and work with the Teamsters, neighborhood, community and elected leaders to develop a plan that will protect these important workers in Starbucks' supply chain," Cales said.