BATH, Maine — The defense subcommittee of the U.S. Senate Appropriations Committee on Thursday passed the 2015 defense spending bill, which includes full funding of nearly $3.43 billion for the DDG-51 and DDG-1000 destroyer construction programs at Bath Iron Works.

The bill, which goes to the full committee, includes $2.67 billion for procurement and $134 million for advance procurement of the DDG-51 program, and $622 million for procurement and research and development of the DDG-1000, according to the office of Sen. Susan Collins, R-Maine, a member of the subcommittee.

The DDG-1000 is the so-called “stealth destroyer” line the Pentagon truncated — due to concerns about high costs — after three ships, all of which will be built at the Bath shipyard. The less expensive DDG-51 class of destroyers, which preceded the “stealth” line, has been restarted.

The funding would allow BIW to continue work on three DDG 1000 ships and three of the Arleigh Burke-class DDG-51s: the DDG-115 and DDG-116, which are already underway, and the DDG-118 for which work will begin this fall, according to BIW spokesman Matt Wickenheiser.

Also included in the bill is an amendment, authored by Collins, that could add another DDG-51 destroyer to the workload at Bath Iron Works, according to Collins staffers.

The amendment acknowledges a 2002 memorandum of understanding among Bath Iron Works, Northrop Grumman and the U.S. Navy, which requires BIW be awarded an additional destroyer if the Navy awards Northrop Grumman an additional San Antonio-class amphibious transport dock ship (LPD-17), estimated to cost $1.8 billion.

The 12-year-old memorandum of understanding transferred four LPD-17s scheduled to be built at BIW to Northrop Grumman, then the lead yard for the San Antonio-class amphibious transport dock ship ( LPD-17), in exchange for four DDG-51 destroyers contracted to Northrop Grumman.

The move was designed to save money and improve workload stability at the three yards, the Navy said at the time.

In 2011, Northrop Grumman spun off its shipbuilding business into Huntington Ingalls Industries Inc. Huntington Ingalls is slated to build 11 LPD-17s.

The memorandum of understanding states that a fourth DDG-51 class ship “or equivalent workload” would be awarded to BIW preceding any award of a 12th amphibious transport vessel.

In June 2013, the Navy awarded BIW contracts for four DDG-51s, while Huntington Ingalls landed contracts for five. In March, the Navy awarded a fifth ship to BIW.

A BIW spokesman said in June the Navy could award BIW one of the DDG-51’s already slated to be built at Huntington Ingalls or as a new appropriation in the 2015 budget.

Collins said Wednesday the inclusion of the amendment marks the first time any congressional committee has acknowledged and recognized the 2002 memorandum of understanding.

“While full funding for an additional LPD is not certain, I am hopeful that if Congress were to fund another LPD to be built by Huntington Ingalls, then, according to this agreement, an additional DDG-51 or equivalent workload would be awarded to the men and women at Bath Iron Works,” she said in a statement.