Canadian National Railway Co. has put a costly railway line in northern Quebec on hold midway through a feasibility study, due in part to delays in mining projects because of low iron ore prices.

The Montreal-based railway had been working with several mining companies and the Caisse de dépôt et placement du Québec on a study into a transportation link for iron ore producers at the Quebec-Labrador border.

CN announced in August that the group was looking at a rail line and terminal handling facility, which analysts estimated could cost $5-billion.

But railway spokesman Louis-Antoine Paquin in said Friday that everything now is on pause.

He wouldn’t say if the Quebec government’s plan to increase mining royalties played a role in the decision.

“It’s a bunch of factors,” he said in an interview.

“There’s a pause because we’re evaluating certain timetables and also it has something to do with some projects of mining companies that they seem to have put on hold at the moment.”

Mr. Paquin wouldn’t say how much has been spent on the partially completed feasibility study. The Caisse declined to comment on the decision.

Rod Cooper, president and chief operating officer of Labrador Iron Mines Holdings Ltd., said last summer that a new terminal handling facility at the Port of Sept-Îles would complement plans for a new dock at the port.

The former Quebec government’s Plan Nord envisaged CN and the Caisse developing a new, 800-kilometre line from the port of Sept-Îles to the Labrador Mining Trough, a major growing source of iron ore.

Cameron Doerksen of National Bank Financial had said the project wouldn’t likely be operational until 2017-18 but could provide large revenues for CN. He had estimated the railway could potentially generate $1.5-billion to $2-billion in annual revenues on top of its current total of nearly $10-billion.

Among industry players that were expected to benefit from the line was railway wood tie supplier Stella-Jones Inc.