BP has banked a $6bn sale of most of Castrol, but the 35% slice it kept, locked up for two years, leaves the oil major tied to the lubricants Brand for a while yet.

A deal done, a stake retained

The FTSE 100 ended Monday 2 November 2026 at 10,761.33, up 31.55 points, or 0.3%, for a fourth straight winning session. BP (LSE:BP.) was not part of the celebration. Its shares dropped 4.37% on the day it completed the sale of a 65% stake in Castrol to Stonepeak Partners for $6bn.

That headline number grabs attention. The detail that matters for the longer story sits underneath it: BP has not walked away. It keeps 35% of Castrol, and that holding is subject to a two-year lock-up. In plain terms, BP has swapped full ownership of the Business for a large cash payment plus a sizeable minority position it cannot sell in the near term.

The new owners have also moved quickly on governance. Former Shell chief executive Ben van Beurden has been appointed chair of the lubricants maker's new board. A one-time boss of BP's biggest London-listed rival now presides over a business in which BP remains a significant shareholder. It is a striking twist, and one that underlines how far Castrol is becoming a standalone company with its own leadership.

Monday's slide had little obvious connection to the Castrol news itself. The reports behind the day's market moves point squarely at oil. Brent Crude fell to $105.09 a barrel at the London close, down from $117.61 on Friday, a drop of roughly $12.52. One US close report had Brent settling 7.63% lower at $104.77, with West Texas Intermediate down 7.36% at $96.46, its steepest one-day fall since 27 July.

The trigger was diplomacy. Reports said Washington and Tehran were weighing renewed indirect negotiations, while talks between Iran and Qatar raised hopes of an end to the US–Iran conflict. Iran was also reported to have offered to reopen the Strait of Hormuz under strict conditions.

For producers, a sharply cheaper barrel is an immediate headwind, and the market priced that in. The FTSE 350 energy sector fell 3.3%. Ithaca Energy (LSE:ITH) was the biggest FTSE 100 faller at -5.94%, BP came next at -4.37% and Shell (LSE:SHEL) shed 2.86%. Against that backdrop, completing a disposal was never going to be the story traders focused on.

What the 35% actually represents

The retained stake gives BP continuing exposure to Castrol's fortunes without the full burden of running it. Whether that proves valuable depends on how the business performs under its new owners and board, and on what Options BP has once the lock-up ends. None of that is knowable today, and no terms beyond the price, the stake split and the lock-up have been verified here.

What can be said is that the arrangement changes the nature of BP's link to Castrol. Before, it was a wholly owned division. Now it is an Investment alongside a private buyer, with the cash already in hand for the majority portion.

Illustration: a simple pro-rata calculation shows the scale involved. If $6bn bought 65%, the implied value of 100% is about $6bn ÷ 0.65 = $9.23bn. On that same basis, BP's 35% would be worth about $9.23bn × 0.35 = $3.23bn. This is arithmetic only. It ignores any debt, adjustments, fees or deal terms not disclosed in the reports used here, and it is not a valuation of the stake.

A two-year lock-up means BP cannot simply sell the remaining stake whenever it chooses. That has two practical effects. First, it keeps BP's interests aligned with Stonepeak's while the new structure beds in. Second, it pushes any further decision on Castrol well beyond the near-term horizon that most trading in BP shares is focused on.

For now, the oil price is doing far more to set BP's share price than the stake ever could. Monday showed that clearly: the sale completed and the shares still fell by more than 4%.

Reading BP against the wider FTSE 100

The broader market told a different tale. Lower oil helped the index's consumer, travel and construction names. Travel and leisure rose 2.7%, construction and materials 2.8%, and consumer goods and services 2.5%. JD Sports Fashion (LSE:JD.) led the FTSE 100 risers with a 4.76% gain, while International Consolidated Airlines Group (LSE:IAG) added 3.8%.

The mid-cap FTSE 250 did even better, climbing 1.4% to 24,795.85. The FTSE 100, with its heavy oil weighting, lagged that move. Because the index is weighted by market value, big constituents such as BP and Shell can drag on it when crude falls, even as many smaller members rally.

Elsewhere, sterling edged up to $1.3417 from $1.3396, and gold climbed to $3,968.02 an ounce. In Europe, the CAC 40 rose almost 1% and the Stoxx 600 reached a two-month high.

BP's shares will also trade against a busy macro week. The Bank of England announces its decision on Thursday 5 November, with Bank Rate at 3.75% and a quarter-point increase to 4% widely expected; markets price it at around 95%. It would be the first hike in more than three years.

UK factory data added to the pressure. The UK Manufacturing PMI rose to 52.8 in October from 51.9, a five-month high. The survey's compilers said resilience and surging input prices "will further shorten the odds of Interest Rate hikes".

Key dates to watch

  • Tuesday 3 November: US midterm elections
  • Thursday 5 November: Bank of England rate decision
  • Thursday 12 November: UK GDP first quarterly estimate for July–September, 7:00am
  • Tuesday 1 December: FTSE 100 December review market-cap data cut-off
  • Wednesday 2 December: December review announcement, after the UK close
  • Monday 21 December: December review changes take effect

The bottom line

BP has turned most of Castrol into cash while keeping a 35% foothold that it must hold for at least two years. That makes the lubricants business a slow-burning part of the BP story rather than a clean exit. On Monday, though, the market had other priorities. A roughly $12 fall in Brent and hopes of US–Iran talks drove BP 4.37% lower, a reminder that for FTSE 100 oil majors, the barrel still sets the tone.