Venture capital investment in startup San Diego companies increased during the first six months of this year but remains near its lowest level in 12 years.

Many venture capital firms have been forced to invest more money into their older, later-stage companies to keep them going, which has resulted in less investment in young startup companies.

In the second quarter, 71 percent of the money invested went to new or early-stage companies, compared with 35 percent nationally.

Still, venture capitalists are being cautious with their investments in younger companies, including those in life sciences, said Dan Kleeburg, partner with Ernst & Young, which also tracks venture capital investing locally in conjunction with Dow Jones/Venture Source.

“With the newer companies, one trend is tranche funding,” Kleeburg said. “That’s where a company might announce a deal that’s $20 million, but it’s being funded in pieces. So you get $5 million now, and then $7 million after reaching certain milestones.”