U.S. stock index futures jumped on Tuesday after a bullish Alcoa forecast boosted the outlook for the commodities sector, signaling a stronger global economy.

Alcoa Inc posted revenues above expectations and forecast a deficit in the aluminum market, sending its shares up 3.1 percent to $9.72 in premarket trading.

Copper prices rose 3.1 percent, the best performance since late November, as markets bet on stronger economies and more demand.

That's the assumption the marketplace is making this morning, for sure, said Art Hogan, managing director of Lazard Capital Markets in New York. This is one day, though. It's not as if we've cured all our problems.

S&P 500 futures rose 13.7 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration of the contract. Dow Jones industrial average futures gained 122 points, and Nasdaq 100 futures added 22.25 points.

Mining stocks also led European markets higher. The STOXX Europe 600 Basic Resources index <.SXPP> rose 3.2 percent and the broad FTSEurofirst 300 <.FTEU3> gained 1.8 percent.

Still, investors were cautious ahead as debt auctions in Spain and Italy later in the week test market appetite in two countries at the forefront of the euro zone debt crisis.

U.S. bank stocks were expected to continue a rebound that has lifted the KBW bank index 6.9 percent so far this year. The Select Sector Financial SPDR exchange-traded fund gained 1.8 percent in light premarket trading.

The U.S. Securities and Exchange Commission has urged banks to publish more details about exposure to European sovereign debt, a factor in the recent bankruptcy of the futures brokerage MF Global Holdings Ltd .

Microsoft Corp added 0.8 percent to $27.97 a day after it said sales of its Kinect sensing device for the Xbox game console hit more than 18 million since its launch over a year ago.

Oshkosh Corp said billionaire investor Carl Icahn may increase his stake to 20 percent from his current 10 percent ownership.

Liz Claiborne Inc cut its annual outlook and said the finance chief was leaving. The shares were down 11.9 percent at $8.75 in light premarket trading.

U.S. stocks ended slightly higher on Monday in a light-volume session as investors stayed cautious ahead of corporate earnings and key auctions for European debt this week.

(Reporting by Rodrigo Campos; editing by Jeffrey Benkoe)

Carl icahn