Canadian National Railway Co. has made a higher bid than Canadian Pacific Railway Co. for Kansas City Southern railway.
CN has offered $29.9-billion US in cash and stock compared with $25.2 billion US that CP has offered.
CN said its purchase of KCS could yield $1-billion US in cost savings.
Both railways see benefits from extending their networks across the United States into Mexico.
“We firmly believe our proposal is far superior to KCS’ existing agreement with CP because it offers superior financial value over the immediate and long term, a more complementary strategic fit, greater choice and efficiencies for customers, and enhanced benefits for employees and local communities,” said CN chairman Robert Pace.