A gas field in the British waters of the North Sea started production, which at its peak, should account for 5 percent of the nation's total, Centrica said.

Centrica owns slightly less than half of the Cygnus field, which is operated by a British subsidiary of French energy company ENGIE. Centrica said gas is now flowing from the field into the British transmission system

"The Cygnus field is hugely important to the country's energy supply, so we are proud that gas is now flowing from the field and into homes and businesses across the United Kingdom," Chris Cox, the managing director for exploration and production for Centrica, said in a statement.

Centrica said that, at peak production, the field should contribute to 5 percent of the nation's total gas production next year and be the largest producing gas field in the British waters of the North Sea.

The production start is a win of sorts for Centrica. The Norwegian subsidiary of the company in early 2016 unloaded about 30 percent of its working interest in three license areas in Norwegian waters following a portfolio review.

Centrica's work at Cygnus started four years ago and the company said the project has already contributed about $1.6 billion to the British economy.

The development comes as Centrica's peers launch new operations in a North Sea once sidelined because of maturing opportunities. British energy company BP in early December said it was drilling, alongside its regional partners, beneath a mature basin in the southern North Sea. If successful, the company said it could open up a new area of potential gas development in the region.

Even though some areas are running dry, BP said the North Sea remained a central component of its portfolio. The company plans to drill up to five exploration wells over the next 18 months and 50 development wells over the next three to four years.

Centrica said "fresh wells" have been already drilled in other parts of the Cygnus field.