Painful cost-cutting and rising sales to automakers helped the nation’s largest aluminum producer return to profitability for the first time in nine months. Alcoa Inc. yesterday also forecast an 11 percent increase in worldwide aluminum demand for the rest of the year. The lightweight metal is used in everything from airplanes to cars to houses.

Alcoa Inc., the largest U.S. aluminum producer, yesterday reported a second-quarter loss of $454 million—smaller than analysts’ estimates after production cuts and work-force reductions helped the company save money. It was Alcoa’s third straight quarterly loss and fresh evidence of slumping orders from key customers in the aerospace, automotive and construction industries as the global recession continued to dampen demand and prices for the lightweight metal.

Kaiser Aluminum is cutting back again at its Bellwood plant in Chesterfield County, eliminating 56 of about 125 jobs and closing the plant temporarily in July. The temporary shutdown of the facility, which produces drive shaft tubes for automotive customers and seamless tubes for service centers, comes in response to planned shutdowns in the automotive industry, a Kaiser spokesman said.

In a bleak start to the earnings season, Alcoa Inc. reported a quarterly loss of $497 million as the stumbling global economy continued to erode prices and demand for the aluminum maker’s products. The Pittsburgh-based company that acquired Henrico County-based Reynolds Metals Co. in 2000 said yesterday that it expects further industrywide production cuts as demand for the lightweight metal remains weak in the coming months.