LONDON (Reuters) -BP said it expects upstream production to rise in the third quarter, reversing earlier guidance for a slight decline, but flagged weak oil trading performance in a trading update ahead of results due on November 4.

The oil major guided for both higher oil and gas output, particularly at its U.S. onshore fields. However, gas prices received were lower and gas trading was described as average.

Energy companies almost never give details of their trading results in order to protect their commercial advantage.

It had previously said it expected slightly lower upstream output than in the second quarter when it produced around 2.3 million barrels of oil equivalent per day.

BP guided for a rise in its refining indicator margin to $15.8 per barrel in the quarter, versus $11.9 per barrel in the previous quarter.

REFINING MARGINS PROVIDE BOOST

The higher refining margins are set to add $300 million to $400 million to BP's results, although some of that will be countered by compliance costs and an unplanned outage at its U.S. Whiting refinery, which was hit by flooding.

BP's shares were down 1.5% at 0830 GMT compared with a 1.4% fall in a broader index of European energy companies.

"BP's 3Q25 trading statement sees the expected tailwinds from higher quarter-on-quarter margins and operational uptime in refining, but this is likely partly offset by weaker oil trading. We trim our estimates," Citi analysts said in a note.

Brent crude oil prices averaged $69.13 per barrel in the third quarter, compared with $67.88 per barrel in the second quarter.

BP expects the prices it received in its gas and low carbon business to result in a $100 million hit compared with the previous three months.

U.S. gas prices averaged $3.07 per million British thermal units in the third quarter, compared with $3.44 per mmBtu in the second quarter, BP said.

Net debt is expected to be broadly flat compared with the previous quarter's $26 billion.

BP expects to write off around $181 million on oil exploration, according to Reuters calculations based on numbers released by BP on Tuesday and previously. It also sees total impairments across other business segments of between $200 million and $500 million in the third quarter.