NEW YORK - Investors are putting the latest stock rally on hold as fears creep up again about the health of banks.

Stocks gave up early gains they made in response to strong profits at industrial company Caterpillar Inc. and reassuring words from Federal Reserve Chairman Ben Bernanke. Weakness in regional banks tugged at the market after Regions Financial Corp. and Comerica Inc. posted second-quarter losses.

Bernanke told Congress the Fed would be able to withdraw its economic stimulus and prevent a resurgence of inflation when the recovery is more secure. In testimony before the House Financial Services Committee he said the central bank won't be making any changes in its stimulus policy in the near future, and that its focus remains "fostering economic recovery."

Some of the day's corporate news was good but wasn't able to support the entire market. Caterpillar joined other companies in issuing an improved 2009 profit forecast, even as it said its second-quarter profit fell 66 percent on weaker sales. The heavy equipment maker is considered a bellwether of the global economy so its forecast was particularly encouraging to investors. Its shares soared about 6 percent.

Meanwhile, chemical maker DuPont Co. and drug company Merck & Co. reported drops in quarterly profit, but results still came in ahead of Wall Street's forecasts.

Companies' reports have largely exceeded expectations so far this earnings season, fostering a renewed sense of optimism in the market and helping to drive the Dow Jones industrials back into the black for the year. But the regional banks' results reminded investors that the banking industry still faces many challeges as they try to recover from the credit crisis and the recession.

In midday trading, the Dow fell 6.27, or 0.1 percent, to 8,841.88. The Standard & Poor's 500 index fell 5.04, or 0.5 percent, to 946.09.

The Nasdaq composite index, which has a large representation of technology stocks, fell 12.37, or 0.7 percent, to 1,896.92 after chip maker Texas Instruments Inc. posted a sharp drop in profits after the end of trading Monday. That stirred some unease about the strength of other tech companies.

About three stocks fell for every two that rose on the New York Stock Exchange, where volume came to 532.4 million shares compared with 457.5 million shares.

Caterpillar jumped $2.28 to $38.95.

Regions Financial fell 52 cents, or 12.9 percent, to $3.52 after it nearly tripled what it set aside for soured loans. Comerica reported a quarterly loss as it booked a charge to pay preferred dividends to the government under the Treasury Department's financial rescue program.