Japan Petroleum Exploration Co. and Teikoku Oil Co. are in talks with the government on their plans to drill for natural gas in the East China Sea near areas claimed by both Japan and China, government sources said Sunday.

The companies intend to merge their provisional concessions with those of two other firms they plan to take over, with test drilling slated to begin in the fiscal year that starts April 1. The government is likely to greenlight the plan, the sources said.

A Chinese consortium is currently carrying out natural gas projects on the Chinese side in an area very near the exclusive economic zone line set by Japan.