Sunoco Inc. (SUN) and the United Steelworkers reached a tentative deal on a contract for workers at the Marcus Hook, Pa. refinery, Sunoco said Tuesday night.

The workers were threatening to strike over this past weekend. The two sides were disagreeing over potential layoffs.

The union also reached a tentative agreement at the Philadelphia refinery on Monday.

-By Susan Daker, Dow Jones Newswires; (713) 547-9208; susan.daker@dowjones.com