TORONTO, Nov 23 (Reuters) - Alcoa Corp and the United Steelworkers have agreed to resume contract talks with a government-appointed conciliator, the union said on Thursday, averting a potential strike at the Becancour, Quebec aluminum smelter.

The collective agreement for 1,030 unionized workers expired late Wednesday night, putting workers in a legal strike position. A majority of workers had earlier voted to reject the company’s contract offer and give their union a strike mandate.

The contract included a two-tier pension plan that is less favorable to new workers and demanded concessions on seniority rights, the union said.

Becancour produces 430,000 metric tonnes of aluminum annually, Alcoa said. Combined with the company’s Deschambault and Baie-Comeau smelters in Quebec, total annual production capacity is nearly 1 million metric tonnes of ingots, plates and billets, Alcoa said.

Alcoa owns 74.95 percent of Becancour with Rio Tinto Alcan holding 25.05 percent. (Reporting by Susan Taylor; Editing by Susan Thomas)