Robeco Private Equity has raised $650 million, reaffirming some venture capitalists' beliefs that investing during the economic downturn is a smart move.

Part of the Robeco Group, which is owned by the Dutch bank Rabobank, the private equity business is raising the money for the Robeco Clean Tech Private Equity II Fund, reported Venture Wire.

Robeco hasn't stopped raising money, however, even though it already had surpassed its $500 million goal.

The investment firm plans to both put most of the money into funds managed by VC firms, with about 40 percent of the money directly in cleantech companies. Robe co is keen on investing in water purification and renewable energy, such assolarand wind power.

Robeco has promised to put money in several funds this year, including the VantagePoint Cleantech Partners II, the second cleantech fund by Vantage Point Venture Partners.

Plenty of VCs have opined about the impact of the troubled global financial market on the investing community in recent months. Many of them have said that raising funds won't be easy.

"I think funds will have a very hard time raising capital in this capital market," said Anup Jacob, managing director of Virgin Green Fund, at the Renewable Energy Finance Forum in Seattle last month (see VCs Predict Greentech Investment Slowdown).

Rob Day, a Boston-based VC who writes the Cleantech Investing blog, wrote last month that the number of cleantech deals is likely to decline in the fourth quarter. Early-stage companies, which won't have to worry about an exit soon, will grab more attention from VCs during the economic downturn.

"So I think (guess?) Q4 will see a moderate decline in the number of cleantech deals overall, a bit of a shift into earlier-stage investing, and a big decline in aggregate dollar amounts," he wrote. "And early stage will be the first to pick back up going forward. Early stage cleantech venture capital remains a very attractive investment area."

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