Quebec government leaders have adopted special legislation that will pave the way for the Societe de transport de Montreal (STM) to acquire new Azur subway trains.

The move will allow STM to order additional Azur units from the Bombardier plant in La Pocatiere, Quebec, the Montreal Gazette reported. The legislation includes a clause that rules out any legal challenges to the purchase, according to the newspaper.

The new law means that STM can begin negotiations for more Azur trains, agency officials said in a press release.

“Once [the negotiations] have been completed, the STM will be able to specify the timeline for commissioning the new trains and certain details related to the agreement,” agency officials added.

The release didn’t state how many new cars STM plans to order. Bombardier’s current contract calls for building 468 cars. The agreement is valued at CA$6.3 billion, according to the Montreal Gazette.

The Quebec government previously asked STM to study scenarios for replacing its MR73 subway cars, which date back to the 1970s. Since it’s not practical to replace all units in the short term, the agency proposed replacing part of the fleet.