Spain's Repsol SA has entered a farm-in agreement with Energean Oil & Gas SA for a 60% stake in two onshore blocks in western Greece, Energean said March 31.

Repsol will become the operator of the Ioannina and Aitoloakarnania blocks and plans to acquire seismic surveys over the areas in the 2017-2019 period.

Energean, Greece's sole oil producer, holds an exploration license in Ioannina and is expected to acquire one for the other block. The company did not disclose the size of the deal, which is subject to Greek approval.

Energean CEO Mathios Rigas said that the agreement was a significant step forward for the development of the Greek oil and gas sector.

"Repsol’s expertise and Energean’s knowledge of the area’s geology will undoubtedly drive forward the possibility of making new discoveries in Western Greece," he added.

A consortium led by France's Total SA (NYSE: TOT) signed earlier this month a deal for deepsea gas exploration in one offshore block in western Greece.