By Steve Tawa

PHILADELPHIA (CBS) — Now that Septa has a tentative agreement with its Regional Rail engineers, talks resumed today with the transit agency’s biggest union, representing bus, subway, and trolley workers.

The tentative agreement with locomotive engineers puts a possible commuter rail strike on the back burner.  But there could still be a job action by workers who drive, fix, and maintain buses, subways, and trolleys.

Members of Transport Workers Union local 234 have been working without a contract since March. They haven’t met face-to-face with Septa negotiators since the summer.  Two days of negotiations are scheduled for this week.

The TWU, which represents more than 5,000 workers, mostly in the City Division, could go on strike with short notice, according to Local 234 leader Willie Brown.

“It’s not a matter of if we strike, it’s a matter of when we strike — that’s where we’re at right now,” he tells KYW Newsradio.

Septa spokeswoman Jerri Williams hopes the two sides find common ground.

“We’ve got some veteran, professional negotiators on both sides of the table, and we’re going to try to get a contract,” she said.

Brown says the workers’ pension plan is unfair.  Although managers and union workers contribute the same amount to their pensions, he says, managers gets three times as much pension as a Local 234 member.  “We have to close that gap,” he says.