Dec 22 (Reuters) - Starbucks ( SBUX ) workers have

expanded their strike to four more U.S. cities, including New

York, the union representing over 10,000 baristas said late on

Saturday.

The five-day strike, which began on Friday and initially

closed Starbucks ( SBUX ) cafes in Los Angeles, Chicago and Seattle, has

added New Jersey, New York, Philadelphia and St. Louis, Workers

United said in a statement. It did not say where the New Jersey

walkout was occurring.

Starbucks ( SBUX ) did not immediately respond to a request for

comment outside regular business hours.

Talks between the coffee chain and the union hit an impasse

with unresolved issues over wages, staffing and schedules,

leading to the strike.

The union is striking in 10 cities, also including

Columbus, Denver and Pittsburgh, during the busy holiday season

that may impact the company's Christmas sales.

Workers United warned on Friday that the strike could reach

"hundreds of stores" by Tuesday, Christmas Eve.

Starbucks ( SBUX ) began negotiations with the union in April. It

said this month it had conducted more than eight bargaining

sessions, during which 30 agreements had been reached.

The company operates more than 11,000 stores in the United

States, employing about 200,000 workers.