LONDON (Reuters) - An agreement between Greece and its euro zone partners is still possible, EU Economics Commissioner Pierre Moscovici told Britain's BBC radio on Wednesday, adding that the future of the currency bloc was at stake in the talks.

Euro zone members have given Greece until the end of the week to come up with fresh proposals in return for loans that will keep the country from crashing out of Europe's currency bloc.

"Today, although difficult, very difficult, an agreement is still possible and more necessary than ever," he said. "Grexit would be a terrible failure, a collective mistake and we are fighting to avoid it."

Moscovici said the bloc was still waiting to see a set of "comprehensive, credible, complete, tangible set of reforms" from Greece, but that he believed the Greek government remained committed to staying in the euro zone.

Moscovici, a former French finance minister, said it was important for Paris and Berlin to act together to convince Greek Prime Minister Alexis Tsipras to deliver a workable proposal.

"We are certainly in a historical moment where the future of the euro zone is at stake," he said. "We need to be conscious of that and to act at a level of responsibility which is as important."

(Reporting by Estelle Shirbon, writing by William James)