THE president and CEO of Canadian Pacific Railway (CP), Mr Fred Green, will today mount a counterattack against a campaign to oust him by Mr Bill Ackman, CEO of a US hedge fund called Pershing Square Capital Management which has a 14.2% shareholding in CP. Ackman believes CP is under-performing - its operating ratio of 81.3% is the worst of the six North American Class 1 railways - and he wants to replace Green with former Canadian National CEO, Mr Hunter Harrison.