Stock index futures pointed to a lower open on Wednesday Dow component Alcoa kicked off the earnings season with its second consecutive quarterly loss and reignited concern about the global economy.

The aluminum producer reported a first-quarter net loss that was worse than Wall Street estimates as metal prices and the auto industry slumped. Shares fell 3.7 percent to $7.50 in premarket trade.

Pulte Homes

said it would buy Texas-based builder Centex for $1.3 billion in stock against the backdrop of a troubled industry.

Intel , the world's largest chipmaker, is unsure of when demand for semiconductors will revive, said Chairman Craig Barrett.

Alcoa serves as the cold water in the face to temper the recent optimism, said Andre Bakhos, president of Princeton Financial Group in Princeton, New Jersey.

Early signs from the global front are not helping and it's further highlighting the negative outlook on earnings and global economy.

S&P 500 futures fell 3.90 points and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures slid 49 points, and Nasdaq 100 futures shed 2.50 points.

European shares fell early on Wednesday, putting them on track for their fourth straight day of losses as investors worried about company earnings and financials weakened.

Asian stocks slid for a second day on Wednesday while the U.S. dollar climbed, with investors fleeing to the sidelines to await companies' business outlooks as what is expected to be a grim earnings season begins.

Sharp Corp <6753.T>, the world's No. 3 LCD TV maker, doubled its loss estimates for the year just ended on a slump in sales of its Tvs and panels, but unveiled plans for a cost-efficient new factory in an effort to cut costs.

German carmaker Daimler forecast a significant drop in revenue in all of its automotive business this year as it pushed back its of when the beleaguered industry might recover.

U.S. stocks slid on Tuesday, hammered by fears that companies will show they struggled in the first quarter as the recession dragged on as the earnings season kicked off with Alcoa.

The Dow Jones industrial average <.DJI> fell 186.29 points, or 2.34 percent, to 7,789.56. The Standard & Poor's 500 Index <.SPX> lost 19.93 points, or 2.39 percent, to 815.55. The Nasdaq Composite Index <.IXIC> gave up 45.10 points, or 2.81 percent, at 1,561.61.

(Reporting by Chuck Mikolajczak; Editing by Theodore d'Afflisio)