NEW YORK - The stock market got a shot of confidence from the start of second-quarter earnings season.

Investors sent stocks sharply higher Tuesday after better-than-expected profits from aluminum maker Alcoa Inc. and railroad operator CSX Corp. The Dow Jones industrial average rose more than 145 points for its sixth straight gain, and the major indexes were up well over 1 percent.

There was more good news from Intel Corp. after the close of trading. The chipmaker reported earnings and revenue that beat analysts' expectations, and it also raised its forecast for the year. Its stock shot up more than 7 percent in after-hours trading.

The companies, among the first to report second-quarter earnings, also issued upbeat forecasts for the rest of the year. That was heartening news for investors who have been concerned that the recovery was stalling, or that the economy might fall back into recession.

"When we go back to earnings and fundamentals, companies are delivering," said Tom Karsten, senior managing partner at Karsten Financial in Fort Worth, Texas.

The Dow rose 146.75, or 1.4 percent, to 10,363.02. The Standard & Poor's 500 index rose 16.59, or 1.5 percent, to 1,095.34, while the Nasdaq composite index rose 43.67, or 2 percent, to 2,242.03.

Alcoa's earnings reports are closely watched because its varied customer base provides a snapshot of a broad range of other industries. CSX also provides insight into economic activity because it ships a wide range of products. And Intel's results are considered a good gauge of the health of the economy since its sales are driven by consumers and businesses buying computers.

Alcoa said global consumption of aluminum will grow this year by more than it had forecast just three months ago. There have been concerns that the global economic recovery will end as many European nations face mounting government debt problems and high unemployment slows growth in the United States.

CSX, meanwhile, said it sees the economy's upward momentum continuing this year.

Frank Ingarra, co-portfolio manager of Hennessy Funds in Stamford, Conn., said the results from Alcoa and CSX lifted the market because they hit on the two themes that traders are looking for in earnings: revenue growth and optimistic outlooks.

"That's why the earnings were so good," Ingarra said. "You saw that top-line growth and good guidance."

Earnings will likely continue to dictate the direction of trading over the next few weeks as hundreds of companies release results. Major banks begin reporting their results on Thursday.