The board of the Massachusetts Bay Transportation Authority has authorized $1 million in additional funding for a bus overhaul contract with the Maine Military Authority, according to Joe Pesaturo, communications director at the Massachusetts Bay Transportation Authority.

The Maine Military Authority, a state-operated company based at the Loring Commerce Centre in Limestone, has been trying to renegotiate a $19 million contract signed in 2014 with the Massachusetts Bay Transportation Authority for the overhaul of 32 dual articulated transit buses.

The Maine Military Authority delivered 11 rebuilt transit buses, but further work was halted in September 2016 after Gov. Paul LePage said the agency underbid the contract and faced a potential shortfall that could cost Maine taxpayers.

As part of a renegotiated agreement, Massachusetts Bay Transportation Authority procurement officials have proposed an additional $2.1 million and a list of provisions for the Maine Military Authority to achieve the completion of all 32 buses.

The Massachusetts Bay Transportation Authority board authorized $1 million of that amount for the time being to help the Maine Military Authority resume work. No contract changes have yet been signed, Pesaturo said Monday afternoon.

According to a presentation by the Massachusetts Bay Transportation Authority procurement chief, the transit agency “determined that [Maine Military Authority] has a clear understanding of the requirements for the successful completion of the remaining vehicles.”

If the full additional $2.1 million is approved, the total cost of the contract would still be less than the $22.4 million figure from the Massachusetts Bay Transportation Authority’s original independent estimate of the refurbishing costs, according to Monday’s presentation.

The Maine Military Authority was the sole bidder on the contract and underbid it by about 17 percent, according to Massachusetts Bay Transportation Authority. Maine Military Authority officials later determined, however, that it was costing more for the overhauls than they anticipated in part because of the complex nature of the transit vehicles and challenges in finding replacement parts.

While the price of refurbishing the buses has increased, the Massachusetts Bay Transportation Authority said it has been satisfied with the overall quality of the 11 buses that have been completed. To help the Maine Military Authority restart work on the four buses currently in process, the Massachusetts Bay Transportation Authority will provide some materials currently in the agency’s inventory.

It is not clear if the proposed changes to the contract will affect LePage’s request to the Legislature for a $7 million funding package to help shore up the Maine Military Authority.

The $7 million package from state surplus revenue would help the Maine Military Authority complete the Massachusetts Bay Transportation Authority contract, seek new contracts and allow the agency to rehire 35 workers who were laid off in December, Maine Military Authority officials said in testimony on Jan. 18 to members of the Legislature’s Joint Standing Committee on Appropriations and Financial Affairs.