Spain's De Guindos insistent that Greece likely to need another aid programme

BARCELONA (Reuters) - Spanish Economy Minister Luis de Guindos said on Wednesday that Greece is unlikely to be able to return to capital markets by June, when an extension of its bailout expires, so it will probably need further support from European partners.

De Guindos - whose talk of a third rescue package for Athens earlier this week prompted denials from other senior euro zone officials that such negotiations were underway - stressed that some form of further aid programme looked likely.

He also reiterated that preliminary estimates pointed to an aid package of between 30 billion euros (21.7 billion pounds) and 50 billion euros.

"If Greece does not recover market access by June (...) we will have to establish some other type of agreement with Greece, call it a pact, a deal, a programme," de Guindos told a conference in Barcelona, adding that Athens looked unlikely to be able to fund itself independently soon.

"We have given ourselves these four months to, one, see what the real situation is, to see how Greece has met conditions and to try and establish what happens next (...), which is fundamentally a third rescue," de Guindos said.

Greek Prime Minister Alexis Tsipras on Monday denied his country needed another international rescue deal, while the spokeswoman for Jeroen Dijsselbloem, who chairs the euro zone finance ministers' group, said no talks were underway.

Tsipras has pledged to dismantle Greece's bailout programme, but since being elected in January has had to make key concessions and extend Athens' current aid programme as the country faces funding problems and tries to fend off a banking crisis.

De Guindos said on Wednesday that the size of any third support deal for Greece had yet to be agreed and that euro zone finance ministers would examine Greece's liquidity needs and debt maturities at a Eurogroup meeting next week.

(Writing by Sarah White; Editing by Julien Toyer and Susan Fenton)