The search for street­cars to run on Toronto’s new Transit City light rail lines could soon be back to square one, potentially delaying the opening of light rail lines on Sheppard East, Finch West and Eglinton Avenue, according to the chair of the TTC.

The TTC has a $1.22 billion contract with Bombardier to replace its fleet of 204 streetcars.

The contract includes an option to negotiate for as many as 368 more LRVs to run on the new suburban Transit City routes owned by the province.

But the Transit City LRVs require less customization because those routes don’t have the steep hills and tight turning requirements of the existing 11 TTC streetcar lines, said Metrolinx CEO Robert Prichard.

The provincial agency has power and ownership over all new transit projects, including vehicles, in the Toronto region. It is working with the TTC on specifications for Transit City cars. When that’s settled — a process that will take months — Metrolinx will pick either Bombardier, the TTC’s preferred supplier, or seek other bidders.

Metrolinx has “the ultimate authority” for the Transit City LRV specifications and getting “a price that’s fair to the people of Ontario for that car,” Pritchard said.