VIENNA- Austrian energy group OMV on Thursday indicated it could be interested in increasing the stake in a Romanian offshore gas project that it currently holds with U.S. firm Exxon Mobil.

The exploration of the Black Sea Neptun block is a joint venture between OMV's Romanian subsidiary Petrom ROSNP.BX and the U.S. company and includes the first deep-water exploration well in Romanian waters. Exxon Mobil plans to exit the venture and has begun providing information to potential buyers.

"We are not currently conducting any concrete negotiations with Exxon Mobil because ... as long as there is no official sales process we cannot negotiate," said OMV exploration chief Johann Pleininger at a news conference. "We are certainly not interested in the full 50% that Exxon Mobil is now offering."

(Reporting by Kirsti Knolle Editing by Michelle Martin) ((kirsti.knolle@thomsonreuters.com; +43 1 2530 1650 13;))