Alcoa Inc., the biggest U.S. aluminum producer, said Tuesday its first-quarter income fell 69 percent as higher costs offset increased revenue, but the results still beat expectations and shares jumped 5 percent.

Net income for the New York-based company declined to $94 million, or nine cents per share, compared with $308 million, or 27 cents per share, in the first quarter of last year.

Excluding one-time items like the negative impact of mark-to-market changes on certain energy contracts and restructuring charges on smelter curtailments, the company earned $105 million, or 10 cents per share. 

Revenue inched up to $6 billion despite a 9 percent drop in aluminum prices and a 13 percent drop in the realized price of alumina.

A consensus of analysts polled by Bloomberg News expected earnings per share of four cents per share and revenue of $5.77 billion.

Shares of the New York-based company jumped after the markets had closed by 47 cents, or 5 percent, to $9.79. In regular trading shares fell 28 cents, or 2.9 percent, to $9.32.

Strong productivity improvements across all businesses, higher realized prices for aluminum, and improved volume and mix were offset somewhat by lower realized alumina price and higher input costs, the company said in a statement.

Alcoa raised its 2012 global growth forecast for the aerospace market 3 percentage points to 14 percent and said it expects global growth in the automotive, commercial transportation, packaging, building and construction and industrial gas turbine markets.

Alcoa affirmed its forecast of a global aluminum supply deficit this year and reaffirmed its forecast that global aluminum demand would grow 7 percent in 2012, on top of the 10 percent growth seen in 2011.