CALGARY - Canadian Pacific Railway Ltd. (CP.TO) says it expects to have more than 500 new high-capacity grain hopper cars in service before the end of 2018.

The Calgary-based company has placed an initial order for 1,000 cars from Hamilton-based National Steel Car and expects to order a total of about 5,900 of the grain hoppers over the next four years.

Canadian Pacific announced few details about the cost of the new grain hopper cars, except that it plans to invest more than half a billion dollars as part of its commitment to the North American agricultural sector.

Rival Canadian National Railway Co. announced a similar order of 1,000 hopper cars in May, also from National Steel Car.

Both companies said their orders were facilitated by federal government changes that encourage railways to make investments to avert service disruptions.

The Transportation Modernization Act includes financial penalties for railways that fail to deliver promised rail cars for grain shipments on time.