Workers for the private company that runs the city’s bus system voted Friday to unionize.

Employees of MV Transportation voted 27-11 to join the Amalgamated Transit Union. Approval came one year after a similar effort failed on a tie.

Officials on both sides of the union-management divide said Lawrence bus riders shouldn’t notice a difference in service now that employees are unionized.

“There’s no reason why it should,” said Mike Sweeten, manager of MV’s Lawrence operations.

Javier Perez, an international vice president for the union, was on hand to observe Friday’s vote. He said employees’ inability to make desired gains in wage, benefit and work-hour issues led to this year’s success after the earlier failure.

“Nothing changed” after the 2001 vote, Perez said. “A majority of people decided the things we said last year were accurate. So they decided to make a change.”

Sweeten disagreed, saying the company had given employees two pay raises since the bus service started in December 2000. New drivers now make $8.75 an hour, up from $8.50 a year ago. But he said there was no room left in the contract with the city  valued at $1.7 million this year  to give workers another bump.

Any significant raise in pay will depend on the city’s largesse next year when the contract with MV Transportation comes up for review, Sweeten said.

“We’re disappointed by the outcome,” he said, ” and we disagree that our employees need a union to speak for them.”

Even after the successful vote, however, employees would not comment on the union.

Perez said union workers would meet to elect a bargaining team and decide the issues they want to negotiate. Riders shouldn’t be worried about the process, he said.

“Anything’s possible, but strike’s not our favorite option  we prefer binding arbitration,” Perez said. “We want to settle things at the negotiating table.”

MV Transportation is willing to work with the group.

“We intend to bargain in good faith,” Sweeten said.

The union will represent all regular full- and part-time drivers, dispatchers, reservationists, utility employees and mechanics who choose to join. Roughly 50 employees are eligible.