(Washington) The American railway regulator gave the green light on Wednesday to the takeover of Kansas City Southern (KCS) by Canadian Pacific (CP).

Surface Transportation Board approval was the final hurdle in CP’s bid to buy KCS for US$31 billion in a deal that would create the only single-line rail network connecting Canada, the United States and Mexico.

The merged railroad will bear the name Canadian Pacific Kansas City, with current CP CEO Keith Creel as president and CEO. The City of Calgary will house the international headquarters.

While it will remain the smallest of the six major railroads in the United States by revenue, it will operate nearly 33,000 miles of track and employ nearly 20,000 people.

It’s been a long and bumpy road to get here, with CP fighting a months-long battle with competitor Canadian National (CN) over the acquisition before CP closed its proposed deal in December 2021.

CN and the US Department of Justice’s antitrust division have expressed concerns about the merger, warning of threats to competition.

Companies in this story: TSX: CP, TSX: CNR