Montreal's transit authority has stopped using its new subway trains following a weekend incident that caused a lengthy shutdown along one of the Metro lines.

The Societe de transport de Montreal says it has pulled from service the 12 trains built by Bombardier (BBDb.TO) and Alstom while it conducts an investigation.

The new trains as well as some older models sustained damage to their electrical contact shoes Saturday in an incident that caused the Orange line to be shut for several hours.

The signalling system and railway track were also damaged.

Bombardier-Alstom spokeswoman Michelle Stein says the new trains didn't cause the incident since damage was sustained by new and old trains alike.

She says the new trains have run without incident since entering service last March.

The consortium is supplying a fleet of 52 rubber-tired trains to replace the city's aging fleet at a cost of $1.2 billion.

The STM plans to place a camera on some trains to try to determine the cause, before putting the trains back into service.