About 80 percent of the workers rejected the contract offer but the president of the local steelworker's union urged the company to continue negotiations.
The company and United Steelworkers had agreed in November to resume contract talks with a government-appointed conciliator.
Becancour produces 430,000 metric tonnes of aluminum annually. Alcoa owns 74.95 percent of Becancour with Rio Tinto Alcan holding 25.05 percent.
(Reporting by Akshara P in Bengaluru; Editing by Shounak Dasgupta)
