The spokesman, who declined to be named in line with corporate policy, did not specify how long supplies would last but said the period would be longer than the three months laid down by EU rules.

Fears of disruptions have grown in recent days with Athens and its international creditors still at odds, raising the possibility that Greece will default at the end of the month. Euro zone leaders will hold an emergency summit on Monday as a last push to break the impasse.

Imports of energy and medicines top the list of products at risk if Greece defaults and moves towards exiting the euro zone.

Hellenic Petroleum covers 65 percent of Greece's energy needs and is obliged to keep fuel reserves for three months under the so-called compulsory stock obligations followed by European oil firms.

"The group has in place a contingency plan for a series of eventualities in line with its established risk management policy," the spokesman said. "This plan extends the security of the supplies for much more than the three-month obligation."

Hellenic Petroleum's Chief Executive Grigorios Stergioulis, part of a Greek mission at an economic forum in St Petersburg, told the semi-state Athens News Agency that the company's regular policy was to hold oil futures contracts to secure oil supplies beyond three months.

(Reporting by Angeliki Koutantou, editing by Deepa Babington/Janet McBride)

Valeurs citées dans l'article : SECURITY, Hellenic Petroleum S.A., McBride plc, CORPORATE