A group of large US freight railroads has reached tentative agreements with unions representing more than 15,000 workers, a step to avoid a widespread strike after years of failed labor talks.

The deals with three of the 12 rail unions come several weeks after a mediation board appointed by the White House issued recommendations including wage increases and expanded health coverage. Railroads including BNSF Railway Co. and Union Pacific Corp. said the terms reflect the board’s recommendations, including a 24% wage increase through 2024, with a 14.1% increase effective immediately, according to a statement Monday by the National Carriers’ Conference Committee.

Railroads and workers have faced years of challenging negotiations, which began in January 2020, shortly after the labor contract froze at 2019 levels. After the National Mediation Board failed to carve out an agreement earlier this summer, the Biden administration formed a presidential emergency board in July to keep 115,000 rail workers across the US from striking.

“We look forward to additional discussions with the unions that have not yet reached tentative agreements,” the carriers’ conference committee, which represents the freight railroads, said in the statement.

The nine remaining unions and major carriers have until mid-September to accept or reject the plan, which isn’t binding for either party. If the plan is rejected, the workers will be free to strike at the conclusion of a second 30-day period. Still, Congress can intervene by passing legislation to require the parties to extend talks, or even to force an agreement.