OAKLAND -- AC Transit and its bus drivers union reached a tentative contract deal Friday, just two days and a few hours before the expiration of a 60-day order not to strike.

Now the deal must be approved by unionized workers and the transit board to wrap up a long and difficult contract renewal for some 1,625 bus drivers and mechanics.

Union members rejected the last two contract accords, and then the union issued a strike notice. In response, AC Transit persuaded Gov. Jerry Brown to declare a 60-day no-strike period that expires 11:59 p.m. Sunday.

"We continue to be optimistic there will no disruption in bus service," said Clarence Johnson, spokesman for the bus carrier for some 197,000 riders per weekday.

Johnson said he was not authorized to release details on the tentative deal between transit district and Amalgamated Transit Union Local 192.

Yvonne Williams, the union president, could not be reached for comment.

Johnson said he expects the union to vote on the contract soon, but he had no date.

Scheduling a vote promptly could be difficult with Christmas and New Year's holidays coming up.

The last deal rejected by the union provided a 9.5 percent pay increase over three years, and made workers begin paying something toward their health insurance. Workers would have continued to pay nothing toward their pensions.

Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff