The adjutant general of the Maine National Guard said officials still don’t have a figure for how much the state underbid on a contract to refurbish Boston buses, but they will meet with officials of the Massachusetts transportation agency next week to see if they can make changes in the deal.

Brig Gen. Douglas Farnham said the Maine Military Authority, a business set up by the state to boost employment at the former Loring Air Force Base in northern Maine, has finished work refurbishing 11 buses owned by the Massachusetts Bay Transportation Authority and workers are still overhauling others. However, he said, the MMA won’t accept delivery of any of the other buses to be refurbished under the $19 million, 32-bus contract until the agency meets with MBTA officials next Tuesday.

Farnham – who is also commissioner of the Maine Department of Defense, Veterans and Emergency Management – oversees the MMA.

Last month, Gov. Paul LePage said he was halting work under the contract, which he said was seriously underbid by Maine officials.

LePage hasn’t said anything more publicly about the contract.

The MBTA has agreed to discuss changes in the contract, Farnham said, although it’s not clear whether the Massachusetts agency can be required to pay more to cover higher costs by the MMA. Farnham said that Maine officials are trying to come up with a dollar figure for changes needed to make the contract profitable, or at least break even, but they haven’t been able to nail down a number yet.

“How much is the part that’s up in the air,” he said. “Part of it is how much the MBTA will work with us. It’s in everyone’s best interests for them to get their buses and for us to get the work.”

He said Maine officials will probably ask the MBTA to increase what the agency will pay for the work or change the scope of work, or possibly both. He said the current contract calls for top-to-bottom overhauls of the articulated buses, which are extra-long and have a joint in the middle to allow the vehicles to navigate tight city corners.

Farnham said the contract calls for the buses to be completely refurbished, with new interiors and work on overhauling the engines and transmissions. The MBTA said it’s happy with the quality of the work so far, Farnham said,

MMA officials recognized that costs were higher than anticipated early on in the work, which began about 18 months ago and was expected to be completed in mid-2017, he said. But MMA administrators hoped that they could adjust costs as the project proceeded, whether through changes in purchasing parts or changes in how the work was done. It eventually became clear that they couldn’t make enough changes to make the work profitable under the contract in place, he said.

Officials at MMA did not return calls seeking comment Tuesday.

The MMA was created after the Stategic Air Command base in Limestone was closed in the early 1990s. Initially, it was successful in providing employment, with more than 500 workers refurbishing Humvees for the military. Farnham said profits from that project went into the state’s General Fund and paid for scholarships to members of the Maine National Guard.

Any losses incurred by the MMA would need to be covered by taxpayers.

After the Humvee project was done, work dried up, Farnham said. Many companies elsewhere in the country that also worked on the Humvees closed, he said, but MMA sought to stay open with smaller projects. The workforce for the MBTA project is only about 50, he said, and some of the employees are also refurbishing buses for Maine school districts.

Farnham said MMA officials may have been overly optimistic about controlling costs when they bid on the MBTA project because the agency hoped to show other prospective customers that the authority could pull off big projects on a tight budget for non-military work.

“This was proof of concept,” he said.

He said no workers have lost their jobs because of the underbidding and he declined to speculate on whether it might make it harder for the MMA to land contracts in the future.

“I guess it depends on whether we learn from it,” Farnham said. “I don’t think it needs to be a negative thing.”

The MMA is “important to Loring Development (which is overseeing re-use of the air base) and it’s important to workers in The County,” he said.