Stelios Stavridis is the second head of HRADF to leave in less than six months, reigniting controversy around Greece's ailing privatisation programme which is a central requirement of its international bailout.

Delays and privatisation receipt shortfalls are a constant headache for the European Union and the International Monetary Fund, which bankroll Greece's 240-billion-euro rescue.

The lenders said last month that they would review the way HRADF was operating, after it emerged that the agency would miss its 2013 revenue target by about 1 billion euros.

"Finance Minister Yannis Stournaras asked today for the resignation of HRADF chairman Stelios Stavridis," the Finance Ministry said in a brief statement.

A ministry official, speaking on condition of anonymity, told Reuters Stavridis was dismissed for "ethical reasons" after Proto Thema reported on Saturday that he travelled last week on the private plane of shipowner Dimitris Melissanidis, a major shareholder of a Czech-Greek consortium which in May agreed to buy a 33 percent stake in state gambling firm OPAP (>> Greek Org of Football Prognostics S.A.).

Stavridis took the flight immediately after the signing of an agreement to finalise the 652-million euro ($869 million) OPAP deal, Proto Thema said. The newspaper also published a photograph showing Stavridis in the plane, smiling next to a female flight attendant.

Stavridis said Melissanidis dropped him off at the Greek island of Cephalonia, which the shipowner would have passed anyway on his way to France.

"He was kind enough to get me from Athens to Cephalonia ... I have nothing to answer for about that," Stavridis told Vima FM radio, adding the outcry about his trip was "hypocritical".

Stavridis, a Swiss-trained engineer and outspoken economic liberal who founded Greece's biggest swimming pool company, was earning 2,940 euros ($3,900) a month as HRADF chief.

Greece's privatisation programme would not suffer from his resignation, said HRADF's chief executive Yannis Emiris, who is keeping his post.

"There will be absolutely no delays to the programme," Emiris told Reuters, rejecting any suggestion the OPAP deal might be reversed as a result of Stavridis's resignation.

The Finance Ministry official confirmed the OPAP deal would not be affected.

Stavridis's predecessor, Takis Athanasopoulos, stepped down after he was charged by a prosecutor with breach of duty over his former role as chairman of a state utility.

(Editing by Alison Williams)

By Harry Papachristou