BATH — The largest union at Bath Iron Works will vote this weekend on a proposed four-year contract that compromises on two of the most divisive issues — altering work rules so shipbuilders can perform additional tasks outside their specialties and outsourcing some components to subcontractors to save money, officials said Wednesday.

The proposal doesn’t do away with those proposals but “it’s not the carte blanche that they were seeking,” said Jay Wadleigh, president of Machinists Union Local S6, which represents 3,500 shipbuilders.

Under the tentative agreement, workers would give up pay raises but receive $2,500 annual bonuses each year; there also would be modest increases in pension contributions but higher health care deductibles and co-pays for workers.

Parts of the contract would go into effect immediately and others would be phased in if members approve the contract during Sunday’s vote at the Augusta Civic Center. If the proposal is voted down, the existing contract that expires on May 22 will remain in effect, and negotiations will resume.

The response in the shipyard was muted Wednesday.

Some workers felt like the company was asking workers to bear too much of the burden of cutting costs.

“There’s all kinds of concessions that the company wants from employees like me, but I don’t see the company giving up anything,” said John Upham, an electrician who’s worked for 37 years in the shipyard.

The shipyard, a General Dynamics subsidiary, initiated early discussions with the union to help it make a competitive bid in the new year on Coast Guard offshore cutters.

The shipyard hasn’t built a Coast Guard ship since the 1930s, but its future hinges on landing the contract. The shipyard’s 6,000-member workforce has been warned that there would be steep cuts — as many as 1,200 jobs — if the yard fails to land the contract for up to 25 cutters over two decades.

Shipyard spokesman Matt Wickenheiser said the tentative agreement announced Wednesday evening and recent investments in facilities provide flexibility to compete in new markets and to help stabilize the workload.

“It continues to respect the seniority of our workforce and provides them with excellent wages and benefits. As important, this agreement increases company pension contributions and holds flat employee health-care payroll contributions, in an age of disappearing pensions and increased health-care contributions required of employees,” he said Wednesday in a statement.

To be competitive, Bath Iron Works President Fred Harris previously sought to have subcontractors build berthing units, lockers and door hatches, all items now built in Bath. He also wanted to update task lists so workers could take on new jobs to eliminate down time and to become more efficient.

Workers opposed changes that would take them out of their specialties, saying past efforts to have workers perform multiple tasks caused unexpected problems instead of making them more efficient. They also resisted the idea of hiring subcontractors, saying they can make the items more cheaply in many cases.

Top Navy officials have told both the union and the company that future contracts will depend on the shipyard’s ability to reduce costs. Shipyard President Fred Harris told shipbuilders at the recent christening of the future USS Peralta: “We have no other option,” he said. “We must change.”

Relations between union members and shipbuilders deteriorated to the point that Bath Iron Works hired a firm led by former U.S. Rep. Dick Gephardt to try to improve labor relations.

“Win or lose, the company has created a morale problem,” said Dan Dowling, an electrician who’s worked in the yard for 31 years and is a former union president. “Whether we end up voting yes or no, we’re going to have a lot of unhappy people. And history shows it takes a long time to get over that stuff.”