CALGARY, AB — Talks of a merger between Canadian Pacific (CP) Railway and CSX Corp. have ended and no further talks are planned, CP announced.

CP gave no concrete reason for ending the talks, but hinted that regulatory hurdles were a concern.

“While regulatory concerns appear to be a major deterrent for many railroads considering combinations, CP believes that given the right structure between the right players, and having thoughtful considerations and remedies to address shipper concerns, regulatory approvals are achievable,” CP said in a statement.

The North American rail industry has some challenges moving freight, such as worsening congestion. CP had proposed an integrated coast-to-coast combination that it said would improve customer service, promote competition and alleviate congestion.

“CP is convinced that the significant problems that beset the industry now will only worsen over time if solutions aren’t put in place immediately,” CP said. “A pro-competition, customer-friendly, safety-focused railway combination is one such solution that could not be ignored on its merits by regulators.”

CP runs across Canada and into the U.S. while CSX runs largely along the East Coast.