The historic stone building, Union Station, was Ottawa's main railway station from 1912 to the mid-1960s. (CBC)

CBC News has learned that Ottawa Mayor Larry O'Brien is working to move the bus station from downtown to the east-end Via Rail station as part of the plan for the city's $2.1-billion light rail system.

If the city's light rail plan goes ahead, it could involve railway stations past and present, plus a new terminal for Greyhound buses.

"When the light rail comes out at the train station that's one intersection that's important for the city," O'Brien said Friday.

"But I have been talking to Greyhound about the opportunity to move the bus station to the train station [on Tremblay Road near Belfast Road] so we have a hub — rail, city buses, LRT and also the Greyhound bus."

Greyhound bus officials in Ottawa did not return calls from CBC News Friday. But O'Brien said he's hoping for a deal in the next nine months.

"It's something I've been working on behind the scenes for a year now with the parties on where and when. There's some progress going on," he said.

Earlier this week it was learned that O'Brien was trying to persuade the federal government to sell the downtown conference centre to the city, so it could be linked the proposed future transit tunnel.

The heritage building is the city's original Union Station, which used to see regular train service between Ottawa and Montreal.

O'Brien said the city is currently in "preliminary stages" of discussion about the station. One idea has the city paying a dollar for the site, with the province kicking in $60 million to $70 million to pay for removal of asbestos and for other improvements to the building.