CALGARY - Canada's second-largest railway company says it's making a half-billion voluntary payment to its pension plan.

Canadian Pacific (TSX:CP) says it will use cash on hand to make the $500-million voluntary prepayment to its defined benefit pension plan.

The Calgary-based company says the payment will reduce the amount it will have to pay towards its pension plans in 2010.

The announcement comes as Canada's largest railway company, Montreal-based Canadian National (TSX:CN), is in the midst of a strike by one of its unions.

The federal government has introduced legislation which orders CN's locomotive engineers back to work and sends outstanding issues to binding arbitration.