Under its latest international bailout with the European Union and the International Monetary Fund, Greece is selling a 31 percent stake in DESFA and Hellenic Petroleum (>> Hellenic Petroleum) is selling its 35 percent stake in the grid. The country needs to conclude the sale by the end of the year.

Spain's Regasificadora Del Noroeste (Reganosa) and a consortium of Italy's Snam (>> Snam), Spain's Enagas (>> Enagas), Belgium's Fluxys (>> Fluxys Belgium) and Dutch Gasunie got the green light last month to carry out a due diligence process before they submit binding bids.

"They (bidders) are in the process of getting access to DESFA's virtual data room," an official with knowledge of the matter told Reuters. "The aim is to have binding bids before the end of the year."

Another source said the offers were expected in December.

Greece's privatisation agency (HRADF) which is handling the sale declined to comment.

A previous deal to sell the stake to Azerbaijan's SOCAR for 400 million euros (358.23 million pounds)collapsed last year after Athens passed legislation raising DESFA's gas tariffs by a lower amount than SOCAR had expected, and SOCAR subsequently sought to lower the acquisition price.

(Reporting by Angeliki Koutantou. Editing by Jane Merriman)

Stocks treated in this article : Snam, Enagas, Hellenic Petroleum, Fluxys Belgium