Dow On Track for 2011's Best Month, Caterpillar Up

A strong showing by Caterpillar and other U.S. industrials' shares led the market higher on Friday, putting the Dow on track for its best month since December.

The blue-chip average was up 4 percent for the month while the S&P has risen 2.7 percent and the Nasdaq 3.2 percent, also heading for its best month of the year.

April's gains, however, were limited by losses at Microsoft Corp., the Nasdaq index's most heavily traded stock, and BlackBerry maker Research in Motion.