Oil majors Exxon Mobil Corp (XOM.N), Royal Dutch Shell Plc (RDSa.L) and France's Total (TOTF.PA) have shown interest in bidding for blocks offered in Sri Lanka's current licensing round.
Italy's ENI (ENI.MI) and India's ONGC Videsh (ONGC.NS) and Cairn India (CAIL.NS) could also bid for the blocks, Saliya Wickramasuriya, head of the Petroleum Resource Development Secretariat (PRDS), told Reuters at an industry event.
Sri Lanka expects to award 13 exploration blocks in the Cauvery and Mannar basins off its northwest coast in the first quarter of 2014.
"(These) six and some smaller companies have shown interest as of now ... on more than one occasion they have visited us and continue to seek clarification on terms of the contracts," Wickramasuriya said.
Sri Lanka has also offered six ultra-deepwater blocks off the southeastern coast for a joint study with PRDS to establish their hydrocarbon potential.
Total and a couple of other companies are eyeing these joint study blocks, Wickramasuriya said.
The first review of proposals will take place next week, followed by an announcement in October, he said.
"We will review every month," Wickramasuriya added.