Venture capitalists opened up their wallets during the second quarter and invested $2.42 billion in Bay Area companies, a robust 27 percent more than they did in the first quarter, and the most they have invested in any quarter since 2001, according to data to be released today.

The figures, part of a survey compiled by Ernst & Young and research group VentureOne, are another sign of a resurgence in venture investing. Last week, a separate report found venture capital firms raised more money during the second quarter than at any time in the past five years.

The buildup of cash should be a good sign for the local job market: Young technology companies typically create most of the new jobs in Silicon Valley, and venture investing helps seed and nurture these companies.

The growth in local investing was reflected nationally, with $6.73 billion, or 7.8 percent, more invested than in the first quarter -- the most in 4 1/2 years.

The popular consumer Internet companies broadly known as 'Web 2.0' comprise the hot sector in information technology, according to a separate study on first-quarter investing. Web 2.0 refers to the second generation of Internet companies that have used new technology tools to give Web sites more sophistication and easier ways to interact with users.

Investors pumped $870 million into Web 2.0 companies in the first quarter, up from $786 million the quarter before, according to PriceWaterhouseCoopers and the National Venture Capital Association.

However, the study defines Web 2.0 companies fairly broadly.

The study included non-consumer companies, such as San Francisco-based Riverbed and Palo Alto-based Netli, two network infrastructure companies that many people wouldn't associate with Web 2.0, but which PwC and NVCA included because they help facilitate the Web 2.0 experience. They raised $20 million and $18 million, respectively.

More traditional Web 2.0 consumer companies, such as Redwood City-based Riya and San Mateo-based Sling Media, were included. Riya raised $15 million to develop technology that recognizes people and other elements in photos to help classify them. Sling Media raised $46.6 million for its service, which allows you to watch TV on the go.

Seven of the top 10 Web 2.0 deals were in Silicon Valley, according to the data, a high proportion eerily reminiscent of the valley-heavy presence of dot-com companies in late 1999.

'People are trying to contrast this with the Internet bubble, and want to know if we're getting in the same risk category we saw developing in late 1999, early 2000,' said Tracy Lefteroff, global managing partner of PwC's venture capital practice. 'You always run that risk, but I still don't see the frenzy to invest in these companies that we saw in the late 1990s.'

Venture capital firms were also drawn to alternative energy in the second quarter, according to the Ernst & Young/VentureOne study. One of the largest deals in the quarter was the $75 million raised by solar company Nanosolar of Palo Alto.

Capital investment in health care companies nationwide increased 25 percent over the same quarter a year ago, reaching $2.24 billion through 160 deals. The biopharmaceutical segment was the major driver of this, with 80 deals and $1.45 billion invested, according to the survey.