Bidders are lining up for BP's North Sea oil fields after the company released confidential sale documents for the £2.5bn package.
The company, which last month confirmed plans to exit the North Sea after 60 years , has started to formally sound out buyers as it seeks a rapid sale of the assets.
It is understood to be seeking a single cash purchaser for its whole portfolio, which comprises five production hubs off the coast of Scotland.
BP issued a "confidential information memorandum" to prospective buyers last week, offering access to its geological and other data, subject to non-disclosure agreements.
According to analysts at Rystad, the most likely purchasers are Neo Next+, Adura, and Ithaca Energy, owned by Israeli firm Delek.
Neo Next+ is widely seen as the leading candidate after recently buying out BP's share of Culzean, the North Sea's largest gas field.
John Knight, Neo's executive chairman, has said he plans further expansion. "Neo Next+ intends to play a leading role in consolidation activity in UK waters for years," he said recently.
At stake in the BP sale are five of the UK's largest remaining production hubs, two in the central North Sea and three lying in Atlantic waters west of Shetland.
The latter includes the Clair and Schiehallion fields, whose estimated eight billion barrels of oil make them the largest known remaining resource in UK waters.
Meg O'Neill, BP's new chief executive , announced the sale shortly after Andy Burnham became Prime Minister – apparently despite Labour pleas beforehand for her to reconsider.
Adura, a joint venture between energy giants Shell and Norway's Equinor, is also said to be keen.
Unlike Neo, it already has assets west of Shetland that could fit well with BP's Clair field operations.
Ithaca Energy, whose talks with BP failed earlier this year, is understood to also be a candidate.
Smaller independent oil companies are also interested, potentially including Serica Energy and Enquest.
They may struggle to find the cash for the whole portfolio, instead hoping for a break-up that would allow them to pick out key assets.
Toby Fulton, from Wood Mackenzie, said: "The financial and technical requirements involved in exploiting BP's UK portfolio point to a small pool of incumbents who know their way around the North Sea."
David Latin, chair of Serica Energy recently confirmed the company's interest.
"Serica is one of the companies that the basin is still very much attracting, not losing. We've built ourselves up through acquisitions from companies like BP. … We hope we're going to continue to invest," he told the BBC.
