Paris-based Olympia, which is one of the oldest fund of hedge funds firms and runs more than $2bn in assets, was previously owned by Sagard Private Equity Partners and other shareholders.
The deal is subject to regulatory approval and closing conditions.
"In a context of consolidation of the fund of hedge funds sector, this transaction reinforces Olympia and provides enhanced access to the important UK market by associating with a growing player," said Rik Battey, partner at Sagard.
Richmond Park was set up by former Dresdner and Goldman Sachs bankers in 2009.