MONTREAL (AP) -- Aluminum producer Rio Tinto Alcan said Thursday it is preparing to restart idled production at its Vaudreuil alumina refinery in Quebec, Canada, due to improved demand.

The company, a division of Anglo-Australian mining giant Rio Tinto Ltd., said it will restart 25 percent of the plant's production, idled in January as "a necessary step to reposition our business."

Orders for aluminum, used in everything from beer cans to window frames, dropped sharply late last year as the global economy deteriorated. Aluminum producers responded by cutting production of the lightweight metal. Alumina is an aluminum ingredient.

Restarting the idled production will not affect the permanent work force at the plant, and some contractors are expected to be recalled to the refinery, Rio Tinto Alcan said.

"Vaudreuil will continue to adjust its operations to maintain its competitiveness," Steve Hodgson, president of bauxite and alumina at Rio Tinto Alcan, said in a statement.

Shares of Rio Tinto PLC slid 58 cents to $182.05 in morning trading.