Pershing, a U.S. fund run by activist investor William Ackman, revealed more than a month ago that it had acquired a 12.2 percent stake in CP, making it the railroad company's largest shareholder. Last month it boosted its stake in CP to 12.4 percent.
Ackman is well-known in the investment community for taking big stakes in companies and working with their management to try to improve the value of the business.
In a regulatory filing on Thursday, Pershing said it has held talks with CP about its business, operations, management and the composition of its board.
While the talks have been productive, Pershing cautioned that there could be no assurances that CP would adopt any of the suggestions that it made.
Pershing has been silent on what its plans are for CP, but Ackman was reported as saying he did not think it should be sold.
CP, which operates a 14,000-mile (22,400 km) rail network across Canada and into the United States, has not commented on any talks between the two sides. (Reuters)
