A month after walking off the job, thousands of Northrop Grumman employees will return to work following their approval Wednesday of the company’s contract proposal that calls for a $2.78 raise an hour over the next three years.

That is $1.22 less than the amount workers originally sought, but 18 cents more than the company’s previous proposal.

“It has been difficult for everyone,” said Bill Glenn, communications director of Northrop Grumman. “Now it’s time to get back to work.”

Tuesday is the first day workers will be mandated to return to their four-day-a-week jobs. Monday is a holiday and Thursday workers don’t have to return but can.

Metal trade workers approved the contract with a 60 percent vote, while 67 percent of electrical workers voted yes, Glenn said.

“We’re proud of the solidarity and commitment that the workers put on the line to bring about the kind of agreement that both the union and the company can be proud of,” said Ron Ault, national president of the AFL-CIO’s Metal Trades Department, in a statement.

In the new contract, first-year workers at Mississippi’s largest private employer will see their average pay rise from $18.32 an hour to $20. The 9.2 percent increase is one of the largest hourly raises in company history for first-year workers, a company statement said.

The proposal calls for an immediate $1.68 raise, and then a boost of 55 cents a year for the next two years.

“This initial increase was designed to quickly and directly address the economic impacts of Hurricane Katrina on our employees,” a statement from the company said.

The Jackson County Civic Center was packed with workers when voting began at 10 a.m. Wednesday. The crowd grew larger by midday.

After union leaders explained the specifics of the contract, angry workers took to a microphone to express complaints with the deal. The throng of voters booed those who had positive statements.

The Sun Herald reported that talk among workers outside the building was laced with negative comments, but more were admitting they voted for the contract than in the past.

The unions had sought a $4 raise, phased in as $2 to return to work and two subsequent $1 raises.

The best wage offer the company had previously made was $2.50 an hour phased in over three years. Union members rejected that plan.

But union leaders urged employees Tuesday to vote yes to the latest version of the contract.

“We believe this agreement addresses the entire range of concerns from the members and their families and we’re recommending a yes vote,” Ault said in a statement released Tuesday.

Under the new plan, the average annual wage would increase from $38,106 to $43,888, and vacation days would increase for workers with one to four years experience, which makes up 30 percent of the current work force.

“This contract provides a very fair financial offer that comprises a competitive wage and benefits package,” said Philip Teel, president of Northrop Grumman Ship Systems, in a statement. “This proposal meets current and future employees’ needs based on the current and potential economics of the Gulf Coast region while staying within a cost structure that is in line with our customer and shareholder requirements.”

The company and unions went back to the bargaining table Monday at the request of a federal mediators after three weeks of inactivity.

Workers went on strike March 8 after twice rejecting company contract offers. Employees at other Northrop shipyards in Gulfport and Louisiana approved new contracts.

Medical insurance for about 7,000 workers affected by the strike ran out Saturday. Interim insurance would have cost them $810 for the month of April. Last Thursday was the last chance workers could return to work and keep their insurance benefits at the company cost of $144 a month.