A new four-year pact with the Hawaii Government Employees Association’s professional and scientific workers will cost the state an additional $276 million, the Abercrombie administration estimates.

The tentative agreement with the unit’s 8,100 state and county workers, which has yet to be ratified by the union, calls for roughly 11 percent pay raises and step adjustments. Workers would also pay 40 percent of their health insurance premiums, down from 50 percent. The cost estimate covers only the state’s portion of the new contract.

Kalbert Young, the state’s budget director, said the administration would recommend that state lawmakers agree to finance the deal — if it is ratified — when they meet later this month in a special session to consider a gay-marriage bill. Lawmakers have the option of waiting until the next regular session in January, but if they do act in special session, workers would get pay raises sooner.

HGEA ratification meetings are scheduled for next week. "After months of working hard to secure a new contract on behalf of our Unit 13 members, the negotiating team has reached a tentative agreement on a four-year contract. The negotiating team will provide more information to members at the upcoming statewide ratification meetings next week," Randy Perreira, the HGEA’s executive director, said in a statement Thursday.

"We strongly encourage the members to take time to review their unit’s agreement, attend the ratification meetings and vote."