Ministers seek to untangle measures to help euro

By Robin Emmott and John O'Donnell

BRUSSELS (Reuters) - Euro zone finance chiefs will try to flesh out plans to reinforce the single currency on Monday but their talks in Brussels may do little more than highlight the limitations of last month's deal to help indebted states and banks.

Decisions on banking supervision, how to use euro zone bailout money, aid to Spain and Cyprus and whether to grant concessions to Greece are likely to take months to finalize, while pressure for action is growing.

Spanish and Italian borrowing costs moved back up near unsustainable levels on Friday as hopes raised by the summit began to fade. Leaders of both countries issued pleas at the weekend for rapid moves to implement the agreement.

"This is where the credibility of the entire European project is at play," Spanish Prime Minister Mariano Rajoy said.

The deal reached by leaders from the 17 nations sharing the euro aims to give the European Central Bank greater oversight of the bloc's banks and to use the euro zone's rescue funds to reduce countries' borrowing costs.

But critical elements were left vague, time frames may already be slipping and ministers could end up meeting again later in July to take firm decisions.

"This is very much the follow on from the summit, but it doesn't mean all details can be set down," said one euro zone diplomat briefed on the Brussels meeting that is due to start at 1700 CET (1500 GMT).

"The issue of ECB supervision is a complex, longer-term issue and not one that can be decided in a few hours."