The government and the union representing federal air traffic controllers on Wednesday agreed to extend their contract for four more years, until July 1, 2016, rather than negotiate for a new one.

The contract between the Federal Aviation Administration and the National Air Traffic Controllers Association, which represents about 15,000 controllers, would have expired Oct. 1.

“This contract extension will provide stability for our workforce, ensure continued collaboration to transform the air traffic system through NextGen [a satellite-based air traffic control system], delivering more on-time and fuel-efficient flights, and continue to provide the safest air transportation system in the world,” acting FAA administrator Michael Huerta and NATCA president Paul Rinaldi said in a joint statement.

Because of a special provision in the law, NATCA is one of the few federal sector unions, along with postal unions, able to bargain over pay. However, during the extension, controllers will receive the same raises as federal employees in general, according to a NATCA spokesman.

Pay raises have been a point of contention along with certain other provisions. During negotiations in 2006, the Bush administration imposed its last offer as the contract after declaring an impasse.

The Obama administration rescinded that decision in 2009 and sent the parties to mediation, where an agreement was reached. The contract revised policies in such areas as flexible work schedules, child-care support, grievances and redeployment of controllers to airports needing more staff. Those provisions will continue under the extension.