LONDON/NEW YORK (Reuters) - BP is seeking buyers for a stake in its U.S. natural gas pipeline network, four people with knowledge of the matter said.

The British energy company could raise up to $3 billion from the sale, two of the people said, with one of them adding that BP may sell up to a 49% stake in the business.

The sale process is part of BP CEO Murray Auchincloss's drive to reduce the company's debt levels, which have risen over the past year, another two people said.

BP declined to comment. All four people were speaking on condition of anonymity as they were not authorised to speak publicly.

With its share price languishing, BP is facing investor pressure to improve performance and profitability amid concerns over the company's energy transition strategy.

It has plans to sell stakes in its Lightsource BP solar business as well as its U.S. onshore wind division and offshore wind operations. Auchincloss, who is seeking to increase cash flow and reduce debt, will update the company's strategy in February.

Net debt rose to $24.3 billion at the end of September, from $22.3 billion a year earlier, due to lower than anticipated asset disposals, BP said in its third quarter results.

The company's shares have lost more than 18% of their value so far this year, a worse performance than any of its rivals. Shell's shares are down 3% year-to-date while ExxonMobil is up 14% and Chevron is nearly 7% higher.

The U.S. oil and gas pipeline sector has undergone increasing consolidation in recent years as production grows and problems with permitting for new pipelines make existing assets more valuable.

BP owns around 1,500 miles (2414 km) of pipelines that transport 1.1 million barrels of crude, natural gas and fuels per day across the United States, according to its website.