Crédit Agricole Indosuez (CAI), the investment banking arm of Crédit Agricole, has bought CPR, the specialist French investment bank and fund management firm, for €680m ($585m).

CAI, which already owns 29.4% of CPR, offered €58 per share for the company, a 23% premium to the previous day's close. The offer price also represents a premium of 62% over CPR's low of €35.7 in May.