LONDON — The French oil giant Total is on the verge of becoming the first major oil company to explore for natural gas and oil in shale rock in Britain.

Under the deal, which may be announced as soon as Monday, Total would commit about $50 million for a roughly 40 percent stake in licenses held by a group of companies in Lincolnshire in the East Midlands, according to three people familiar with the matter who spoke on condition of anonymity because the agreement has not yet been signed.

Total’s participation would be a vote of confidence in the government of Prime Minister David Cameron, which has been trying to promote shale gas as an alternative to declining production of oil and gas in the North Sea, despite opposition from local communities and environmental groups. Total, a major offshore oil and gas producer in Britain, apparently wants to expand its role.

Surging production of oil and gas from shale rock has sharply lowered energy prices in the United States and helped make its industry more competitive, though it has also brought criticism from environmental advocates. Britain, however, is the lone country in Western Europe that has encouraged the exploration of shale gas, which is produced through hydraulic fracturing, or fracking, which uses a high-pressure mix of water, sand and chemicals.