The head of state-owned gas producer Romgaz, Razvan Popescu, told reporters Romania could export to Moldova and other neighbouring countries in the future.

Speaking alongside him, OMV Petrom's Chief Executive Christina Verchere also said domestic gas demand will rise by the end of the decade while onshore gas fields decrease.

The two companies on Wednesday greenlit the development of the long-awaited Neptun Deep project off the Black Sea coast.

One of the European Union's most significant natural gas deposits, OMV Petrom, majority-controlled by Austria's OMV, estimated the deep water project would cost 4 billion euros ($4.36 billion) to be split evenly between the two companies, with most of that to be spent in 2024-2026.

Neptun Deep is expected to hold recoverable volumes of around 100 billion cubic metres (bcm) of gas.

Verchere estimated the project creating state revenue totalling 20 billion euros over its lifetime.

Romgaz took out a syndicated loan to pay for its stake in the project, and Popescu said it could refinance that with bond issues. He said the company would seek a rating and would look at two separate issues worth an indicative amount of 1 billion euros.

The two companies will sell gas separately in the project, they said.

OMV Petrom also said it was going to a Paris arbitrage court seeking clarification from Romania's government over free market principles in its offshore law. However, this would not delay the project's timeline.

(Reporting by Luiza Ilie, writing by Jason Hovet; editing by David Evans)