As contract talks continue to drag on without progress, workers at Southern California’s major supermarkets will vote later this month on whether to authorize their union leaders to declare a strike.

The announcement of the strike authorization vote came late Monday after a round of contract negotiations between leaders of the seven United Food and Commercial Workers locals and representatives of Vons, Albertsons, Pavilions and Ralphs.

According to union sources, the vote will be held June 24-25.

Such a vote doesn’t mean a work stoppage is imminent and is often used by unions to put pressure on employers during negotiations. It gives union negotiators consent of the members to call a strike if they deem it necessary.

The announcement indicates UFCW’s frustration after three months of stalled contract talks. The two sides met Monday and Tuesday, with the next session scheduled for July 10, 11 and 12.

“The corporate negotiators continue to offer a contract that does not value their employees,” John Grant, president of Local 770, which represents Los Angeles County workers, said in an emailed statement.

John Votava, Ralphs’ director of corporate affairs, said in an email that store representatives will “continue negotiating a fair agreement for our associates and our company.” He did not discuss the pending strike vote by the union.

Representatives of Albertsons, Vons and Pavillions have not responded to requests for comment.

Some 60,000 unionized employees at the major groceries have been working without a contract since the old deal expired on March 3. Negotiations on a new contract, which have mostly been held during two- day sessions on alternate weeks, have produced little progress.

Greg Conger, president of Local 324, which represents Orange County workers, said Tuesday’s scheduled session, moderated by a federal mediator, went on as scheduled despite Monday’s strike vote announcement..

“There has been absolutely no progress whatsoever,” Conger said early Tuesday before the session started. “It’s not going well at all.”

On its website, UFCW leaders said the grocery stores’ leadership is offering a contract that cut the top salaries for general merchandise clerks and cut wages for cashiers by downgrading their job designation. Wage increases for other employees would come to less than 1%.

Also, the union said the chains’ plan for financing the workers’ health care coverage would put the insurance plan at the risk of bankruptcy.

“The problem we’re having is that these chains are undervaluing their workforce,” said Joe Duffle, president of Inland Empire-based Local 1167.

In its announcement late Monday, UFCW said the corporations that own the groceries gave executives pay increases of as much as 34% last year and paid hundreds of millions of dollars in dividends to investors.

Ralphs, owned by Cincinnati-based Kroger Co., is the only one of the chains that is publicly traded and in March reported $259 million in profits for its most recent quarter. Its next earnings announcement is due next week.

Albertsons, Vons and Pavilions are privately owned and do not report earnings.