CHICAGO - Arizona union workers have reached a tentative agreement with grocers Kroger Co and Safeway Inc, averting a potential strike that had been scheduled to begin on Friday.

The union plans to submit the tentative pact, reached late on Thursday night, to its members and recommend they approve it, the United Food and Commercial Workers Union Local 99, Kroger and Safeway said on Friday.

The companies agreed to extend their existing contract pending the outcome of that vote, the parties said.

Some 25,000 union workers had been preparing for a Friday evening strike deadline if a contract agreement was not reached.

Nearly 250 stores, including Safeway and Kroger's Fry's Food Stores and Smith's chains, are set to keep operating as usual.

Details of the agreement are not being released until the union can present the settlement to its members for a vote.

UFCW members in Southern California participated in a five-month lockout and strike in 2003 and 2004. It was the longest work stoppage in the history of the U.S. grocery industry and accounted for more than $1 billion in lost sales. (Reporting by Jessica Wohl, editing by Dave Zimmerman and Lisa Von Ahn)