U.S. stock index futures rose ahead of Wall Street's opening on Tuesday, with a speech by Federal Reserve Chairman Ben Bernanke likely to take centre stage as corporate and economic data diaries look thin.

At 5:30 a.m. EST, the Dow Jones future was up 0.2 percent and the S&P 500 future and the Nasdaq future were both 0.3 percent higher.

The indicative Dow Jones index, which tracks how the Dow stocks are traded in Frankfurt, was up 0.3 percent.

S&P 500 companies due to report quarterly earnings include food processor and ethanol maker Archer-Daniels-Midland, brewer Molson Coors and software services provider Cognizant Technology Solutions.

Tenet Healthcare reported a $0.12 loss per share for the third quarter compared with expectations of a $0.07 per share loss, according to Reuters Estimates.

Sun Microsystems could also be in the spotlight after its shares fell 2.8 percent in extended trade on Monday, hit by lower than expected revenues.

Bernanke is scheduled to speak at 1:40 p.m. EST on Community Development at a meeting on microfinance in San Antonio, Texas.

Fed watchers will be on the lookout for any signals of further monetary easing on top of the two key rate cuts for a total reduction of 75 basis points in September and October.

Many U.S. banks have made massive write-downs on risky loans and some analysts fear that such losses may restrict lending and aggravate a looming slowdown in economic growth.

The reintermediation that has occurred in the wake of these dislocations also makes credit conditions harder to evaluate, as it is unclear how much this largely unintended balance sheet expansion may impinge on banks' willingness and ability to extend credit voluntarily, Goldman Sachs said in a note.

SUB-PRIME SPILL-OVER

Commerzbank said the tightening in financial conditions would dampen growth and noted that the Federal Open Market Committee's (FOMC) rate cuts, which boosted equity markets, had been aimed at preventing the sub-prime crisis from spilling over into the economy in general.

This concern is likely to prompt it to lower rates again at its next two meetings by 25 basis points each time to 4.0 percent, Commerzbank said.

Morgan Stanley saw risks for U.S. growth skewed to weakness, with growth near zero over the next few months possible.

We think the Fed has some more work to do. We see the FOMC on hold in December before cutting another 25 basis points in January, to 4.25 percent, where we expect the funds target to hold through 2008, Morgan Stanley said.

The dollar struck fresh all-time lows against the euro and a basket of major currencies in early European trade on Tuesday as concerns persisted about the impact of the credit crunch on the U.S. economy.

Data due on Tuesday include ICSC/UBS's weekly chain store sales at 1245 GMT, Redbook's weekly retail sales at 1355 GMT and the ABC/Washington Post weekly consumer comfort index at 2200 GMT.

On Monday, U.S. stocks fell after Citigroup's warning of billions more in loan losses compounded fears that the credit crunch could get worse.

The Dow Jones industrial average closed 0.4 percent lower, the S&P 500 lost 0.5 percent and the Nasdaq Compositealso dropped 0.5 percent.

(Editing by Paul Bolding)

U.S. Ben Bernanke