Buyout firm Charterhouse Capital Partners has sold consultancy Environmental Resources Management for a more than two-times return, as it attempts to raise up to €3.5 billion for its 10th fund.

Charterhouse has sold UK-based ERM to the private equity arm of Canadian pension scheme Omers for an enterprise value of $1.7 billion, according to a statement from the buyer on Monday. Another large Canadian investor - the Alberta Investment Management Corporation - will co-invest in the deal.