Montgomery County public school employees can look forward to their first raise in three years under a tentative budget deal announced Monday.

The settlement between the school district’s employee unions and the Board of Education would provide an average ­increase of about 3.4 percent — after a three-year freeze in cost-of-living increases and a two-year freeze in step increases.

“Our employees have given up a lot in the last three years,” Superintendent Joshua P. Starr said during a news conference Monday morning. “We believe it is time to ensure that their compensation meets the increased demands of the future.”

The deal signals a slightly more optimistic fiscal forecast after a period of austerity. Other school districts, including Fairfax and Prince George’s counties, also are trying to negotiate some form of compensation increase in the coming year, although rising health-care and pension costs continue to strain local budgets.

The salary increases are part of the Montgomery school system’s $2.1 billion budget for the fiscal year that starts July 1. The spending plan for the 146,000-student system represents a 2 percent increase over current annual spending and meets the maintenance-of-effort requirement, a newly clarified Maryland law that requires at least a constant level of per-student funding year-to-year.

Early uncertainty about state-level funding slowed negotiations this year after state lawmakers left Annapolis in April without approving new taxes. A special session held last week restored funding for public education.

Under the new plan, all employees hired before Feb. 1, 2012, would receive a salary increase in July. Those no longer eligible for step increases would get a 2 percent raise. The proposal must be ratified by the unions. A final vote by the school board is scheduled for June 14.

School officials said part of the $47 million cost of the compensation increases would be offset by $27 million in savings achieved partly by a higher-than-expected number of retirements this year.

The budget deal also includes increases to employee co-pays for doctor visits and prescriptions, which are expected to save $7.5 million. Health insurance premiums for Montgomery school employees, the lowest of any school district in the region, would remain unchanged.

Other Montgomery County employees also are expected to get a raise next fiscal year in the form of $2,000 bonuses. Gino Renne, president of the Montgomery County Government Employee Organization, sent a letter to County Council members this month decrying the “ever-widening gap” in compensation between school employees and other government workers.

Doug Prouty, president of the Montgomery County Education Association, said “stability” should be a priority for all county workers, not just educators.

“We think all employees deserve a light at the end of the tunnel,” he said.