The chief executive of Coller Capital, one of Europe's most well-known secondaries private equity firms, has unexpectedly stepped down from the role, citing "compelling personal reasons" for his decision, which comes less than a month after the firm closed its latest fund.

Tim Jones, who is the deputy chief investment officer as well as CEO, will start "winding down his responsibilities immediately" and will become a non-executive special adviser to Coller Capital, the firm said in a statement on January 29.