Ex-Google Ventures head Bill Maris is raising a huge VC fund

Bill Maris, the former head of Google Ventures, is raising money for his own venture capital fund, according to people familiar with the matter.

Maris, who left Alphabet's (GOOGL) start-up investing arm in August, has preliminary plans to raise between $350 million and $500 million, though no amount has been set, said the sources, who asked not to be named because his talks with investors are confidential.

Despite the weakest tech IPO market since the financial crisis, institutions are pouring money into venture capital funds. U.S. VCs raised over $14 billion in the first quarter, the most in a decade, and followed up with an additional $8.8 billion in the second quarter, according to the National Venture Capital Association.

Whether Maris can replicate his Google success operating on his own is the big question limited partners face as they consider putting in money.

Maris started Google Ventures, now known as GV, in 2009 as a way for the internet giant to re-invest in the start-up ecosystem. The firm struck quick success thanks to the Google brand and the ability to give emerging companies valuable resources like cloud-computing infrastructure along with help from specialists in engineering, design and recruiting.

Under Maris's leadership, GV made winning bets on Uber, Nest Labs and Jet.com. It also invested in HomeAway (AWAY), HubSpot and RetailMeNot (SALE) prior to their initial public offerings and has stakes in Slack, DocuSign and Blue Bottle Coffee.

After Theranos's improprieties were uncovered by The Wall Street Journal last year, Maris told Business Insider that a GV life science investor looked at the medical device company and the firm passed because "it wasn't that difficult for anyone to determine that things may not be what they seem here." He told TechCrunch in February that GV opted against backing Zenefits, but made mistakes by not getting into companies including Airbnb, Palantir and Snapchat.

Maris's abrupt departure in August came a year after Google founders Larry Page and Sergey Brin reorganized the company and created Alphabet (GOOGL) as the parent, with Page as CEO. GV was slotted into the "other bets" category, which includes brands and units that are removed from Google's core internet business. Autonomous cars, Nest thermostats and the anti-aging division Calico are also in that category.

Now that the group "other bets" is broken out in Google's financials, the pressure is on to show returns. That's coincided with some high-profile executive departures. Nest founder Tony Fadell left the company in June and Chris Urmson, the technology chief of Google's self-driving car project, stepped away in August.

Maris didn't respond to a request for comment. He hasn't spoken publicly about his post-GV plans and told The New York Times in an August interview that he intended to spend more time with his wife and then 11-month-old child while working on his next project.

Maris started his career investing in biotechnology and healthcare companies for Swedish money management firm Investor AB. During the dot-com boom, he founded web hosting provider Burlee.com, which was eventually sold to Web.com.

In addition to building GV up to a vehicle with 300 investments and $2.4 billion under management, he also turned it into a full-service firm inside of Alphabet, populated with professional engineers, recruiters and marketing experts.

David Krane, an early Google employee who started as communications director in 2000 and joined GV in 2010, succeeded Maris as the venture arm's CEO.