Knight Vinke, the US activist asset manager, is steeling itself for a three to four month fight to break up Suez Group, the French water and power conglomerate. Its plan has already been rejected by Suez and its major shareholders.

Eric Knight, managing director of Knight Vinke, which is backed and partly owned by Calpers, the California Public Employees' Retirement System, said eight "major world-class institutions" including Calpers supported the bid to force Suez to sell its 50.1% stake in Belgian energy subsidiary Electrabel.