Billionaire investor Bill Ackman said Monday he had invested once again in Canadian Pacific Railway Co., a decade after he replaced the railroad’s board of directors and implemented the late Hunter Harrison as chief executive officer in a high-profile proxy battle. 

Ackman disclosed in a regulatory filing that his Pershing Square Capital Management held roughly 2.8 million shares in CP Rail at the end of December. The investor has since added to his position and currently has economic exposure of roughly 14.8 million shares, or US$1.2 billion, in stock and forward contracts that it intends to exercise, a spokesman for the firm confirmed. 

The investor indicated that his second investment in the railway is likely to be less combative, commending the company’s chief executive officer, Keith Creel, who he helped recruit from rival Canadian National Railway Co. 

“One of our greatest investment regrets was selling CP a number of years ago. Keith and the team have done a superb job since,” Ackman said in an emailed statement. “We are delighted to again be an owner of this remarkable and growing franchise at a time when transcontinental rail infrastructure could not be more important for our economy and our continent.”

A representative for CP Rail declined to comment. 

The investment marks a return for Ackman, who served on CP Rail’s board from 2012 to 2016. The investment was one of Pershing Square’s most successful, returning about US$2.6 billion in profit to the firm. 

Shares in CP Rail rose 3.6 per cent to US$80.61 as of 10:18 a.m. in New York on Monday, giving the railway a market value of roughly US$74.9 billion.