A mission of European officials and the International Monetary Fund to Greece has been delayed by the volcanic ash cloud and will arrive on April 21 if possible, Greece's Finance Ministry said on Sunday.

Struggling under a huge budget shortfall and debt pile, Greece requested the talks with the European Union, the European Central Bank and the IMF last week to go over details of a potential aid deal agreed by euro zone states.

The mission had been scheduled to arrive in Athens on Monday to discuss a three-year policy programme for Greece that investors are increasingly convinced will lead the debt-stricken country to tap the bailout.

The ministry said widespread flight cancellations had forced the meetings back at least two days.

The new scheduled day for the start of consultations is Wednesday, April 21, if conditions allow, the ministry said in a statement.

The Mediterranean country of 11 million has yet to ask for the package, which at an estimated 45 billion euros ($62.91 billion) in the first year would be the largest such bailout ever attempted.

IMF officials have said the mission should last 15 days and any agreement would be finalized shortly afterward by its board.

On Saturday, Finance Minister George Papaconstantinou said it would take one week, two weeks maximum for euro zone countries to trigger the mechanism if Greece were to ask for it.

Investors and Greek media see that as increasingly likely since a bid by euro zone leaders to flesh out its details has failed to rein in the spike in borrowing costs that have complicated Greece's deficit-cutting plans.

The certainty is becoming stronger day by day that resorting to the support mechanism is already a one-way road and the International Monetary Fund's role will be upgraded from a supervisor to a lender, daily ETHNOS wrote in a Sunday column.

(Reporting by Angeliki Koutantou; writing by Michael Winfrey; Editing by Charles Dick)