SAN FRANCISCO — Venture capitalists invested $6.24 billion in startups during the third quarter, putting the industry on course for its busiest year since the dot-com bust.

The July-September volume, spread across 797 deals nationwide, represented an 11 percent increase from $5.63 billion at the same time last year, according to data released today by PricewaterhouseCoopers, Thomson Financial and the National Venture Capital Association.

It marked the third consecutive quarter in which venture capitalists have invested at least $6 billion — the biggest burst of activity since the industry was dumping money into startups struggling to survive the dot-com meltdown in 2001 and early 2002.

The investment flow could be even more brisk, because the industry has raised about $65 billion since June 2004. But venture capitalists have shown some restraint, investing under $53 billion during the same time.

"We are pleased to see deal and dollar levels remain relatively stable, as this is indicative of the discipline being applied to investment decisions," said Mark Heeson, president of the National Venture Capital Association.

Through the first nine months of the year, venture capitalists had invested a total of $19.2 billion. Barring an unanticipated fourth-quarter downturn, this year's venture investments should be the highest since the high-tech financiers anted up $40.5 billion in 2001 as they sifted through the dot-com carnage.

Burned by the massive losses in that debacle, venture capitalists went into financial hibernation through 2002 and part of 2003.

As they have gradually picked up their investment pace, venture capitalist have shifted much of their attention to biotechnology. That sector has attracted $3.2 billion in venture capital so far this year, more than any other industry.

Venture capitalists also are flocking to the Internet again. In the third quarter, the industry poured $1.07 billion into startups whose fortunes are tied to the Web — the most in any three-month period since early 2002. The mood still isn't anywhere close to the fervor of the dot-com boom, when venture capitalists were flooding the Internet industry with more than $10 billion per quarter.

Google's planned $1.65 billion acquisition of online video-share site YouTube Inc. — a 20-month-old startup backed with just $11.5 million in venture capital — is likely to divert more money to the Internet, predicted Tracy Lefteroff, PricewaterhouseCoopers' global managing partner of venture capital.