Greece has awarded concessions to Hellenic Petroleum and Energean Oil & Gas for onshore gas exploration and exploitation in three fields in the west of the country, the Energy Ministry said on Feb. 4.

Hellenic Petroleum, Greece's biggest oil refiner, won two of the concesssions and the country's sole oil producer Energean Oil & Gas one, the ministry said in a statement.

Greece, which clinched a third bailout with international creditors in August, has made several fruitless attempts over the last 50 years to find big oil and gas reserves. Its debt crisis has prompted the country to step up those efforts.

The companies submitted bids for the blocks last year.

Hellenic Petroleum - in a venture with Italy's Edison and Ireland's Petroceltic - and Energean Oil were the winners of drilling licenses for three onshore and offshore blocks in western Greece awarded in 2014.