The City of Ottawa faces a $177-million lawsuit from the companies contracted to build the north-south light rail line that city council cancelled in December.

Siemens Canada, PCL Constructors and Ottawa LRT Corp. filed the lawsuit late Tuesday afternoon seeking damages from the cancellation of the $778-million contract they were awarded last July, the City of Ottawa confirmed Wednesday.

"Right now, we're leaving it with the city solicitor," said Mike Patton, spokesman for Mayor Larry O'Brien.

The lawsuit came less than 24 hours before the mayor's task force on transportation was to release its new transit plan for the region. O'Brien assembled the task force just after the light rail contract was cancelled.

"The timing is interesting," said Coun. Steve Desroches on CBC's Ottawa Morning on Wednesday, but he added that it should not impede the city's future transit planning. "Lawsuit or not, we've got to get to work and start implementing solutions."

Desroches said councillors were not surprised by the lawsuit and are being briefed on its implications.

The city council led by former mayor Bob Chiarelli approved the contract with Siemens-PCL/Dufferin to design, build and maintain an electric light rail line running from Barrhaven to the University of Ottawa. The federal and provincial governments had each committed $200 million to the plan.

In December, a newly elected city council led by Mayor Larry O'Brien cancelled the contract.

In February, Siemens offered to settle out of court for $175 million or revive the original plan for $70 million. The city declined.

One month earlier, O'Brien assembled his task force on transportation, led by former transport minister David Collenette. It released its recommended light rail plan Wednesday morning.