The statement from CP, Canada's second biggest railway, came after Ackman's Pershing Square Capital Management, CP's biggest investor, said late on Monday that it intended to nominate five new directors at CP's annual meeting on May 17.
Pershing Square kicked off the battle for the heart of CP in October last year when it announced it had bought what is now a 14.2 percent stake and later said it had a plan to turn around the railroad, and replace the chief executive.
The hedge fund's board nominees are Ackman, Pershing Square partner Paul Hilal, management consultant Gary Colter, energy industry executive Rebecca MacDonald and former Onex Corp executive Anthony Melman.
CP's board is made up of 15 directors, 13 of whom are independent. The directors come from the rail industry, as well as other sectors including energy, natural resources, food and agriculture, and have experience in law, government, banking and finance, said CP Chairman John Cleghorn, a former CEO of Royal Bank of Canada, the country's biggest bank.
Ackman wants to replace CP's CEO Fred Green with former Canadian National Railway CEO Hunter Harrison. Ackman says Harrison would be able to improve CP's operations as he did at CN as CEO between 2003 and 2009.
CP has the weakest operating ratio - an important barometer of efficiency in the railroad industry - out of North America's six big railroads. CN has the strongest.
Harrison said he would be "proud" and "honoured" to lead CP if the board decided he was the best candidate for the job.
"I'm proud of the work we did at CN, and the positive impact that improving its performance had on shareholders, employees, customers and Canada," Harrison said in a regulatory filing.
"With the right board and executive leadership, I believe Canadian Pacific can achieve just as dramatic a turnaround and enjoy its rightful position as a leader in the North American rail industry," he said.
The battle for CP has pulled CN into the widening debate. On Monday, it said it had stopped paying retirement benefits of $40 million to Harrison as it believes he is breaching his contractual obligations because of his involvement in Ackman's plans for CP. It has asked an Illinois court to rule if its action is lawful.
Ackman said there is so little merit to CN's lawsuit that Pershing Square is prepared to guarantee Harrison's retirement benefits if CN prevails in court, the Globe and Mail reported. (Reuters)
