American Airlines and the union representing its flight attendants said they have reached agreement on a new contract that includes pay raises.

Terms of the proposal were not disclosed. The agreement, covering 28,000 workers, faces a union ratification vote.

The Association of Professional Flight Attendants previously rejected an American offer that would have increased pay immediately by 18% followed by annual 2% raises. The union was seeking 33% upfront, followed by four annual increases of 6% each. Flight attendants haven’t received raises since 2019.

Union President Julie Hedrick said Friday the deal “will put billions of additional dollars into compensation and work rules for our flight attendant workgroup.

American, which is based in Fort Worth, Texas, said the deal “will provide immediate financial and quality-of-life improvements for American’s flight attendants. It’s a contract we’re proud of and one our flight attendants have earned.”

Flight attendants voted last year to authorize a strike, and union leadership had raised the threat of a walkout this fall.

However, federal law covering the airline industry makes a strike nearly impossible unless federal mediators determine that more negotiations would be pointless. The union asked the National Mediation Board for permission to begin a 30-day countdown to a strike, but the panel rejected the request, determining that the two sides could still reach an agreement.

President Joe Biden said that officials in his administration, including Transportation Secretary Pete Buttigieg and acting Labor Secretary Julie Su, had worked “to help both sides secure this agreement, which averts a strike that would have been devastating for the industry and consumers.”