NEW YORK: Alcoa Inc posted a third consecutive quarterly loss on Wednesday, but cost cuts helped the largest US aluminum maker beat Wall Street estimates by a large margin, sending its stock higher.

Chief Executive Officer Klaus Kleinfeld later told analysts there were signs that weak demand for aluminum - which has prompted production cuts and plummeting metals prices in the last nine months - might be easing.

"We still have challenging global markets, but there are some pockets of growth," he said, citing such near-term catalysts as China, production curtailments, destocking of aluminum inventories and government stimulus programs.