Gene Yoon is leaving Goldman Sachs (GS) to manage a new $500 million private equity fund, Fortune has learned. Sources say that the new effort will officially launch in May, and that it will be bankrolled by a European family office.

Yoon has spent more than four years running private equity for Goldman’s Americas Special Situations Group, which focuses on growth equity and mid-market private equity investing. According to CapitalIQ, his current portfolio company board seats include LifeLock, Picis, Amber Road and Northface University.

Prior to joining Goldman in July 2007, Yoon had been a partner with Boston-based private equity firm Great Hill Partners. Word is that his new team will include at least one former Great Hill colleague: Philip Yates, who quietly stepped down from his principal position last month.

Yoon also has worked as a banker with DLJ and as director of corporate development for a VC-backed broadband start-up called Geocast Network Systems.

Neither Yoon nor Goldman Sachs have responded to requests for comment. If that changes, this post will be updated.

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