School officials and the Teachers Association of Newport have reached a tentative agreement on a new contract, Supt. John Ambrogi announced yesterday.

The next step is for the union membership to ratify the contract, which would then be followed by a vote of the School Committee.

Ambrogi said he did not know when the union would vote and union president Stephanie Martland could not immediately be reached for comment.

Ambrogi said the accord was reached during a negotiating session that began at 3 p.m. Thursday and ended about three hours later. He declined to discuss the agreement in great detail, saying only that it is a multiyear pact.

The current three-year contract lasts through tomorrow, with teachers scheduled to return to school Tuesday. Students begin classes the following day.

The current contract required teachers, for the first time, to share in the cost of their health insurance. Their annual contribution now stands at 10 percent of the cost of their premiums.

The agreement also ended lifetime health coverage for teachers hired during and after the 2006-’07 school year and anyone with fewer than 10 years of service in Newport schools. Teachers who retired after 2005 and remained in the lifetime-coverage plan now pay 15 percent of their premiums.

The “buyback” that teachers receive for not accepting health coverage is 50 percent of the premium, with a cap of $5,800.

Salary increases were 3.25 percent the first year and 3.75 last year and this year. The base salary this year for a top-scale teacher is $67,263, excluding additional pay for advanced coursework.

The last major labor unrest in Newport took place in 1995, when teachers struck for seven days.

rsalit@projo.com