The U.S. Postal Service and a major union began contract talks Thursday as the agency continued to face huge financial losses.

The Postal Service’s current contract with the American Postal Workers Union expires May 20.

The agency has proposed such cost-cutting moves as ending Saturday mail delivery, only to have them turned aside by Congress.

The union has proposed that postal customers be able to set up accounts where they could get checks cashed and pay bills. Post offices offered some banking services until 1967.

The Postal Service reported a 4.3 percent increase in operating revenue in the October-December 2014 period, but a net loss of $754 million, much of it due to the requirement that it pre-fund retiree health benefits.

“A congressional mandate that forces the agency to pre-fund retiree health-care benefits 75 years into the future is being used as a pretext to destroy a national treasure,” the union president, Mark Dimondstein, said before the negotiating session. “Management has shortened hours at neighborhood post offices, closed mail processing centers, lowered delivery standards and slowed mail delivery.”

Postmaster General Megan Brennan said both sides share the goal of negotiating a contract that “enhances our ability to serve our customers and is fair to postal employees.” Brennan took over the job Feb. 1.

(AP)