BP has put its entire UK North Sea oil and gas business up for sale under a wider $20 billion portfolio restructuring, OilPrice reported, as independent producers with substantial interests in the basin also pursue growth overseas. The operations produced about 117,000 barrels of oil equivalent a day in 2025, representing roughly 5% of BP’s worldwide output, and employed around 1,100 people.

The planned disposal follows departures by Exxon Mobil and Chevron, while Shell and TotalEnergies have transferred their UK North Sea interests into joint ventures. According to OilPrice, basin production has fallen from approximately 4.5 million barrels of oil equivalent a day around the start of the millennium to about 1 million today. The outlet also identified shifting government policy and regulatory uncertainty as factors behind the retreat.

Upstream profits currently face a headline tax rate of 78%, including the 38% Energy Profits Levy. Its proposed replacement, the Oil and Gas Revenue Levy, would charge 35% on revenues above thresholds of $90 a barrel for oil and 90p a therm for gas. Below those thresholds, producers would face the 40% base tax rate. The change is scheduled for March 2030, although Offshore Energies UK wants implementation brought forward to January 2027.

Harbour Energy has reduced its reliance on Britain through its $11.2 billion purchase of Wintershall Dea’s upstream portfolio outside Russia in 2024. That acquisition more than doubled output. Its development pipeline includes a 15% interest in Argentina’s SESA LNG project, targeted to start by the end of 2027. EnQuest, meanwhile, agreed in June to acquire interests in four Malaysian offshore production-sharing contracts for up to $833 million, substantially expanding its Southeast Asian business.

Ithaca Energy is also diversifying, agreeing in early October to buy Suncor’s offshore Newfoundland interests for $860 million upfront and potential additional payments. In Britain, it owns 20% of Rosebank, whose original consent was overturned by a court over the treatment of emissions from burning its oil. OilPrice cited chair Yaniv Friedman’s warning to the Financial Times that Ithaca would probably stop further British investment if the government withheld approval.