Fairfax Connector bus workers have ended a strike as a union and a county contractor agreed to continue negotiating toward a new contract without a work stoppage, officials said Sunday.

Regular bus service on all 91 Connector routes is expected to resume on Monday in time for the morning commute, according to Fairfax County transportation officials, the county’s contractor, Transdev, and the Amalgamated Transit Union.

More than 500 bus drivers and other employees went on strike on Thursday after ATU, the union representing them, was unable to negotiate a new collective bargaining agreement with multinational transit company Transdev after the last agreement expired on Nov. 30. Workers are seeking better annual raises in their negotiations.

“We still have items to negotiate, but our riders come first and foremost for us. We are going back to work because their support and that of elected officials and allies have helped us make significant advances at the table,” ATU International President John Costa said in a statement. “We do reserve the right to walk off the job again if the good faith bargaining by Transdev disappears.”

Fairfax County transportation officials said they expect to resume full weekday service beginning on Monday. Riders can check for updates at fairfaxconnector.com.

“The parties are continuing to bargain in good faith and hope to come to a contract soon,” Transdev company spokeswoman Mitun Seguin said in a statement. “We look forward to returning to regular service levels tomorrow morning.”

The agreement comes after Fairfax County officials had signaled they would fine Transdev if the company was unable to keep regular service going during the strike. About 30,000 people ride the Fairfax Connector on an average weekday. The Connector is Virginia’s largest public bus service.

The bus strike was one of two affecting Northern Virginia. Nearly 130 bus operators, mechanics and utility workers at a Metrobus garage in Lorton, Va., are nearing their 50th day on strike. The Cinder Bed Road bus garage is a Metrobus satellite facility that is also run by Transdev. Employees walked out on Oct. 24 seeking a collective bargaining agreement that sets worker pay, raises, benefits and worker schedules closer to what Metro pays its Metrobus employees.

The Cinder Bed Road strike has caused the cancellation of 18 routes that are operated from the garage. Those routes will remain shut down on Monday, according to Metro’s website. Union officials report no progress in those talks. Last week, the Northern Virginia Transit Commission, which appoints a board member to Metro on Virginia’s behalf, passed a resolution urging Metro to take a more “active role” in resolving the labor dispute.

Metro General Manager Paul J. Wiedefeld has repeatedly said the transit authority will not intervene in the situation, which he called a contract dispute between the union and Metro’s contractor.