British Columbia's government is pushing to end a nearly four-decades-old ban on offshore oil and natural gas drilling to encourage exploration, the province's energy minister said.

Fields off Canada's westernmost province's shores hold as much as 10 billion barrels of oil and 40 trillion cubic feet of natural gas, according to government estimates. It could be the biggest offshore reserves for any province based on these estimates, topping Newfoundland on the east coast.

British Columbia is working to get a federal and provincial ban lifted. Talks with the former Liberal Party government started four years ago with limited progress. The province will now negotiate with the new Conservative Party government of Stephen Harper, a native of the oil-rich province of Alberta.

``It's significant, in fact too significant not to go forth,'' Richard Neufeld, the province's minister of Mines, Energy & Petroleum Resources, said in an interview yesterday in Toronto.

Chevron Corp., the world's fourth-largest oil company, owns a refinery in the province. It paid for a stake in the fields in 1970 allowing for exploration and drilling if the ban were lifted. The Royal Dutch/Shell Group of Cos. had drilled 14 wells in the area by 1969, before the ban was imposed.

Neither Chevron nor Shell has released the results of test wells drilled in the region.

The bans were imposed to prohibit tanker traffic on the channel between British Columbia and Vancouver Island. Federal and provincial governments were close to lifting the ban in the late 1980s. Talks were shelved after the Exxon Valdez tanker struck a reef off the Alaska coast, spilling about 40 million liters of crude oil into the Pacific Ocean near British Columbia in 1989.

Lift Ban `Sooner'

"We want to actually work with" the federal government to get the ban lifted "sooner, rather than later," Neufeld said. British Columbia would be able to reap royalties from its natural resources similar to Alberta and Newfoundland and Labrador if companies were allowed to pursue exploration.