Boston:  Symantec, the biggest maker of security software, said on Wednesday its quarterly profit tripled, and it gave an outlook that topped market expectations, as it kept a tight control on spending.

Shares of the US-based maker of Norton virus protection programs rose 4.5 per cent following the March quarter results, which analysts said also benefited from improvements Symantec made to its products over the past year.

"It's strength across the board," FBR analyst Daniel Ives said. "You have a more content sales force with a stronger product cycle. That's a good position to be in, especially with macro headwinds."

Symantec is proving to be less susceptible to the economic slowdown than other companies, chief executive John Thompson told Reuters. Six months ago, he had said that he was concerned that the worsening economy might hurt Symantec's results.

"I've learned I'm not a very good economic forecaster," Thompson said. "But more importantly we have businesses and technologies that are not deferrable."

Symantec reported fiscal fourth-quarter net income of $186 million, or 22 cents per share, compared with $61 million, or seven cents, a year earlier.

Profit excluding items was 36 cents per share, beating the average analyst forecast of 33 cents, according to Reuters Estimates. Revenue rose 13 per cent from a year earlier to $1.54 billion, matching Wall Street expectations.

Thompson said the revenue growth was partly due to a change in the formula that Symantec uses to compensate some of its sales representatives. The company is rolling out the new incentive scheme more broadly, and the change should continue to help sales, he added.