GO Transit and the union representing bus operators and ticket agents have reached a tentative agreement, averting a strike that could have stranded tens of thousands of commuters beginning Monday.

Details of the contract deal were not initially released to the public.

News of the settlement came a day after both sides returned to the negotiating table with a provincial conciliator.

Wages and job security were key issues in the dispute.

GO's bus operators, support staff and ticket agents last week voted 96 per cent against the company's latest contract offer.

Rejecting the deal put workers in a legal strike position as of 12:01 a.m. Monday. If employees walked off the job, they could have disrupted the morning commute for tens of thousands of residents who rely on GO buses around the Greater Toronto Area.

While the planned job action wouldn't have directly affected GO train operators, an Amalgamated Transit Union official said the striking workers would have set up pickets at GO Transit stations and disrupt service.

GO Transit moves about 165,000 commuters every day, with its 1,800 buses transporting about 30,000 passengers. About 75 per cent of riders travel to and from Toronto.

The unionized employees could have also been locked out by the company if they chose not to strike.

With files from CTV's Austin Delaney