U.S. stock index futures pointed to a slightly higher open on Wednesday as investors looked ahead to congressional testimony from Federal Reserve Chairman Ben Bernanke for clues to the U.S. central bank's thinking on the economy.

Investors have taken a wait-and-see approach this week and a firmer market direction is expected when Bernanke starts his semiannual testimony on monetary policy and the state of the economy before the U.S. House Financial Services Committee this morning.

Todd Leone, head of listed trading at Cowen & Co in New York, said investors would look for clues about the course of interest rates and job creation. Stocks tumbled Tuesday as an unexpected fall in consumer sentiment rattled investor confidence in an economic recovery.

Everybody is waiting for Bernanke, he said. If he signals at all that they're going to raise rates, it's going to be a negative. But I think he's going to be reserved.

S&P 500 futures were up 0.8 points and above 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 rose 11 point, and Nasdaq 100 futures added 4 points.

Shares in Autodesk Inc gained 7.2 percent to $27.50 in premarket trade after the architectural software company posted better-than-expected quarterly results late Tuesday.

On the economic front, the Commerce Dept is to release new home sales for January. Economists surveyed by Reuters forecast a total 360,000 annualized units in the month, compared with 342,000 in December.

In one positive sign from the housing market, U.S. luxury homebuilder Toll Brothers Inc posted a narrower-than-expected quarterly loss and said it sees improvement in the beleaguered sector. The shares rose 3.4 percent to $19.54 premarket.

H&R Block Inc fell 15.8 percent to $16.61 premarket after the largest U.S. tax preparer said it would miss its fiscal 2010 outlook as high unemployment has led to a drop in tax filings.

(Reporting by Edward Krudy; editing by Jeffrey Benkoe)