Venture capital is an area prime for growth, said Russell Steenberg, global head of BlackRock private equity partners.

“When it works it can work spectacularly well,” he said, “but you need to have been invested in the mid-2000s.”

Steenberg pointed to Accel Partners, which invested $12.7 million in Facebook back in 2005. Accel has reportedly made billions off of the deal. Despite all the criticism of Facebook’s IPO, those who invested in the company back in the mid-2000s have done well, he said.

Steenberg made the comments yesterday at an alternative investors’ roundtable hosted by BlackRock. Steenberg, who founded BlackRock PEP in 1999, was one of several firm executives who spoke. BlackRock PEP manages fund-of-funds and direct co-investments. The unit has  $7.1 billion in commitments. Last year, BlackRock announced it was building out its private equity capability, adding three execs from Merrill Lynch.

Such lofty VC expectations aren’t all that rare except for the fact that it is Steenberg, a private equity exec, doing the talking (he is also a Fenway Partners co-founder, by the way). PE generally doesn’t pay much attention to venture capital, given the sector’s poor historical averages. But Triago, the global placement agent, said recently that VC could be one of the best investment opportunities around. BlackRock PEP, as an FOF, has invested in funds that invest in venture capital, said a spokesman, who declined to disclose how much was committed to the asset class.

Later, Steenberg told me on the sidelines of the event that he doesn’t think it’s too late to invest in venture capital. Recent IPOs in social media, like LinkedIn, show that venture capital “does work,” he said. “When the public markets have an appetite for risk then you can make a whole lot of money.”

He noted that 21% of U.S. GDP last year came from companies that were started with venture capital. Much money is being made with good companies that were started with VC, he said. However, the public markets aren’t open now for IPOs.  “When the markets open up you can take advantage of [it],” he said.