ATHENS, Aug 11 (Reuters) - Greece and international lenders negotiating terms of a new multi-billion euro bailout on Tuesday concluded on final fiscal targets, aiming for a primary surplus from 2016, a government official said.

The targets, tweaked from an earlier baseline scenario, foresee a 0.25 percent of gross domestic product primary budget deficit in 2015, turning into a 0.5 percent surplus from 2016, 1.75 percent in 2017 and 3.5 percent surplus in 2018, the official said.

"The targets for the primary budget have been finalised," the official said on the sidelines of talks underway between Greek government officials and representatives of international lenders in Athens.

"It was also agreed that no new measures would be introduced in 2015 and 2016," the official said.

Greece was discussing the terms of a bailout worth up to 86 billion euros. It is anxious to conclude a deal before a debt repayment to the ECB which falls due on Aug.20.

(Reporting By George Georgiopoulos, writing by Michele Kambas)