BRUSSELS (AFP) - Euro zone finance ministers suspended last-ditch talks on Greece's bailout overnight after failing to reach a deal, Finland's minister said on Saturday.

"End of Eurogroup session. To be continued tomorrow (Sunday)," Alexander Stubb said on Twitter after nine hours of talks ended inconclusively.

Maltese Prime Minister Joseph Muscat, who is due to attend a summit of euro zone leaders in Brussels on Sunday afternoon, tweeted: "Briefed about inconclusive Eurogroup meeting. It will be a long day."

Dutch Finance Minister and Eurogroup president Jeroen Dijsselbloem said talks were "very difficult" but euro zone finance ministers were still working for a deal.

"We have had an in-depth discussion of the Greek proposals, the issue of credibility and trust was discussed and also of course financial issues involved, but we haven't concluded our discussions," he told reporters.

"It is still very difficult but work is still in progress," he said.