U.S. stocks rallied, sending benchmark indexes up the most since at least March, as better- than-estimated earnings at companies from Motorola Inc. to Starwood Hotels & Resorts Worldwide Inc. added to evidence the economy is strengthening.

Motorola, the largest U.S. mobile-phone maker, advanced 3.5 percent after reporting an unexpected profit, and Starwood rose 5.7 percent. Palm Inc. surged 26 percent as Hewlett-Packard Co. agreed to buy the maker of Pre phones for about $1.2 billion. BP Plc, Transocean Ltd. and Cameron International Corp. plunged after the U.S. Coast Guard said an oil well in the Gulf of Mexico is leaking five times faster than previous estimates.

The Standard & Poor’s 500 Index gained 1.3 percent to 1,206.77 at 4 p.m. in New York. The Dow Jones Industrial Average rallied 122.05 points, or 1.1 percent, to 11,167.32. It was the biggest gain since March 5 for both measures. The Nasdaq-100 Index jumped 1.8 percent for its best rally since November.

(Source: Bloomberg.com)