Defense Secretary Robert Gates has proposed that General Dynamics’ Bath Iron Works build all three next-generation destroyers, a decision that could provide the shipbuilder with “a steady workload for many, many years,” Sen. Susan Collins said Monday.

The costly destroyer survived Pentagon scrutiny even as several other high-profile programs, such as the F-22 fighter jet and the presidential helicopter, did not.

Bath is already building the first of the stealthy destroyers and the second was supposed to be built by Northrop Grumman’s Ingalls shipyard in Mississippi. The Pentagon’s proposal would take one ship away from Northrop Grumman and award it — along with a third ship — to the Maine shipyard, Collins said.

The Pentagon’s preference to build all three ships in Bath could serve to stabilize the work force as well as lower costs for the ships, said Collins, R-Maine.

“In my discussions with Pentagon officials, they said their goal was to achieve both stability and efficiency. By building all three ships in one yard, they can take advantage of economies of scale and the learning curve,” said Collins, a member of the Senate Armed Services Committee.

The changes could be good for Northrop, as well, because the Ingalls shipyard would be first in line to build more of the existing line of Arleigh Burke destroyers, Gates said.

Margaret Mitchell-Jones, a Northrop spokeswoman, described the agreement as a reallocation of destroyer construction that benefits the Navy and contractors.

U.S. Sen. Roger Wicker called the decision “positive news.”

“This plan calls for the continuation of the DDG-51 program — a ship that Gulf Coast workers have proven they can build and will continue to build into the future,” Wicker said in a statement. “This is a great example of our shipyard working with the Navy on a plan that will provide them with the ships they need to meet the threats of today and tomorrow while ensuring a strong shipbuilding work load on the Gulf Coast.”

The proposal is not a done deal, however.

The two defense contractors are negotiating terms of severing the Northrop Grumman contract. The proposal also would require approval of Congress, where the House Armed Services Committee has been reluctant to fund the DDG-1000 program.

It’s in the interest of both shipyards to go with the Pentagon plan to preserve jobs, Gates suggested. If the plan fails, Gates said, the Navy would scale back to only one DDG-1000 warship in Bath and review options for building more Arleigh Burke destroyers.

The futuristic-looking Zumwalt was originally conceived as a stealth warship that could pound the shore with heavy firepower from 100 miles away. It features composite materials, an electric-drive propulsion and an unconventional hull.

Displacing about 14,500 tons, the ship is 50 percent larger than its mainline destroyers but will have half the crew thanks to automated systems.

Critics have questioned the military necessity of the ship, as well as the cost that has grown as the Navy has scaled back the program. Each of the ships is expected to cost twice the $1.3 billion price tag of the latest Arleigh Burke destroyers.

Bath Iron Works, with 5,700 shipbuilders, has long said it will build whatever ships the Navy wants. It simply needs more work. Over the past year, the shipyard has been laying off workers as the Arleigh Burke program winds down.

“In this economic climate, it’s wonderful to have some good news that translates into real jobs for Maine workers,” Collins said.