Media outlets say Yokohama Tire Manufacturing Virginia president Tesuro Murakami announced the contract's signing on Monday.
Members of United Steelworkers Local 1023 ratified the contract earlier this month. The union represents about 750 hourly workers at the plant.
The contract includes a provision that the plant will remain open during the life of the labor agreement. The contract also continues union members' pension plan.
The Salem plant manufactures passenger, high performance and light-truck tires.