A bidding war is breaking out for Kansas City Southern, with Canadian National Railway making a $33.7 billion cash-and-stock offer for the railway.

The bid trumps a $25 billion cash-and-stock proposal made by Canadian Pacific last month.

Shares of Kansas City Southern jumped more than 18% in today’s premarket trading. CN’s stock fell 9%. Shares of Canadian Pacific Railway Ltd. rose 2.6%.

CN said its offer is worth $325 per Kansas City Southern share. Kansas City Southern shareholders would receive $200 in cash and 1.059 shares of CN common stock for each share. The transaction would include about $3.8 billion in Kansas City Southern debt.

If the two companies were to combine, it would create a business connecting ports and rails in the U.S., Mexico and Canada.

“CN and Kansas City Southern have highly complementary networks with limited overlap that will enable them to accelerate growth in single-owner, single-operator, end-to-end service across North America,” CN President and CEO JJ Ruest said in a statement.

In contrast, Canadian Pacific said its proposed deal would create a combined company that would operate about 20,000 miles of railway, employ 20,000 people and generate annual revenue of about $8.7 billion.

A representative for Kansas City Southern didn’t immediately respond to an email seeking comment.