Canadian Pacific Railway Ltd. had a merger proposal with U.S. railroad CSX Corp. turned away some time in the past week, said people familiar with the matter.

It’s not clear whether Calgary-based Canadian Pacific will return with another proposal, said the people, who asked not to be named because the matter is private. The two companies together would have a market value of about $62.5 billion, according to data compiled by Bloomberg. The Wall Street Journal reported the overture earlier Sunday.

“CSX has a longstanding policy of not commenting on such rumors,” Melanie Cost, a spokeswoman for the Jacksonville, Florida-based freight carrier, wrote in an e-mail. A Canadian Pacific spokesman, Marty Cej, said: “We don’t comment on market rumor and speculation.”

A combination would create a carrier with transcontinental reach, connecting CSX’s network in the eastern U.S. with a Canadian Pacific system spanning the width of Canada. Even with CSX’s backing, a deal would face regulatory scrutiny. Pressure from U.S. officials forced Burlington Northern Santa Fe to abandon a takeover of Canadian National Railway Co. in 2000.

Canadian Pacific Chief Executive Officer Hunter Harrison floated the idea of a U.S.-Canadian rail merger in an Oct. 3 Bloomberg Television interview, saying “any east-west combination” would be possible.

Canadian Pacific could make another approach to CSX or may consider another target, one of the people said.

Ackman Interest

Canadian Pacific is Canada’s second-largest carrier, behind Canadian National. The U.S. industry is dominated by four carriers, with CSX and Norfolk Southern Co. east of the Mississippi River and Union Pacific Corp. and BNSF Railway operating in the west. CSX is the third-biggest U.S. carrier.

Harrison, the former CEO of Canadian National, was hired out of retirement in 2012 after activist investor Bill Ackman’s Pershing Square Capital Management began buying shares in Canadian Pacific and pushed for the ouster of incumbent Fred Green.

CSX is more than twice Canadian Pacific’s size when measured by sales, with $12 billion in 2013 revenue. Canadian Pacific’s total was C$6.13 billion ($5.49 billion).