Oil majors BP, Royal Dutch Shell and Statoil are in talks to buy Toreador Resources, a US company exploring for oil in France, according to US press reports.
The companies have signed confidentiality agreements with Toreador, which has a market capitalisation of $210m, according to the New York Times.
Toreador has the right to develop 649,000 acres, with an additional 153,000 acres pending regulatory approval, in the Paris Basin, where an estimated 65 billion barrels of oil are believed to be in the source rock, according to the report.
New drilling technology has recently opened up drilling for oil and gas in complex rock formations, including shale.
The oil majors have yet to comment on the talks.