Years ago, when we made more site visits, I used to go out to Castrol’s Technology Centre near Pangbourne. The journey was half the fun. Pangbourne is a proper little riverside village, as British as they come, and to reach the office you cross the Thames on a private toll bridge, one of only two left on the river. Once you pay your toll, you arrive in Oxfordshire, head up the hill, and instead of a science lab you find an Edwardian manor house. It felt more like a golf club than a research centre, and of all the bp sites I visited, it’s the one I remember most fondly.
So when bp agreed last December to sell a 65% stake in Castrol, I paid more attention than I usually do to news of a sale like this.
The buyer is Stonepeak, a US investment firm that specialises in infrastructure and real assets. The deal values the whole of Castrol, including its debts, at $10.1 billion. Castrol isn’t a business in trouble. When the deal was announced, bp pointed to nine straight quarters of year-on-year earnings growth. bp keeps the other 35% in a new joint venture, with two board seats, and has agreed not to sell that stake for two years. The EU, China and Australia have cleared the deal, and bp expects it to be completed by the end of 2026.
The main reason for selling was debt. At the end of September 2025, bp’s net debt was $26.1 billion, against a target of $14 billion to $18 billion by the end of 2027. bp said all of the roughly $6 billion it expects from the sale would go towards that target. In February it also stopped buying back its own shares, so the spare cash could pay down debt instead.
Ten months on, bp expects to have hit the target without the Castrol money. Its trading statement on 13 October said net debt should be $13.5 billion to $14.5 billion at the end of September, more than a year early. High oil and gas prices helped, along with the paused buybacks and the sale of other businesses. The Castrol sale hasn’t been completed, so none of its $6 billion is in that figure.
On the 13 October figures, putting the Castrol money towards debt as planned would take net debt below its target range. If the target has already been hit, bp could instead decide to use the money for something else. Either way, what bp aims for next is the question for its strategy update in New York on 15 December. If you work at bp or hold its shares, keep an eye on what it says.
Whatever bp does with the money, when I hear the name Castrol I’ll still picture that building on the hill above the Thames, and the people who worked there.
If you work at Castrol, the company should tell you what happens to your share awards and pension under the new ownership. If you or someone you know has a Castrol connection and would like to go over their plans, we’d be glad to help.
Want to receive more insights like this directly in your inbox? Sign up to our bp Insights newsletter for regular updates and analysis specifically for the bp community, based on our 25+ years of experience.
Want to learn more about how we help bp Leaders optimise their finances? Explore our bp services page here. If you’d like to discuss your specific situation, you can get in touch with our team directly.
We’ve helped bp employees and alumni make the most of their benefits for over 25 years. Emery Little is independent and is not affiliated with or endorsed by the bp group, including BP Pension Trustees Limited, on behalf of the BP Pension Fund. That’s why our guidance is objective and focused only on your best interests.
