OIL producer BP yesterday caused more concern for UK pension funds after plunging into the red for the first time in 18 years as it racked up a $32.2bn bill for the Gulf of Mexico spill.

BP, which also confirmed the departure of under-fire chief executive Tony Hayward, posted a loss of $17bn for the April-June period following the Deepwater Horizon oil accident.

Yesterday, the firm also put about ten per cent of its oil and gas assets up for sale as it looks to raise $30bn over the next 18 months.

The financial figures also give further concern to pension fund investors in the UK, with the Gulf of Mexico spill set to cause havoc.

Nearly every pension investor has a stake in BP’s fortunes, as the oil firm accounts for £1 of every £7 of dividend income paid out by the companies in the FTSE 100 index of leading shares.

In addition, the decrease in BP’s share price since oil started spilling into the Gulf of Mexico on April 20 will also have taken billions of pounds off the value of UK investor pension pots.

Mr Hayward, who has become deeply unpopular in the US through a series of PR blunders since the crisis began, is to be replaced by US citizen Bob Dudley. He will step down on October 1 with a pay-off of one year’s salary – £1.045m – and an £11m pension pot.

He will remain on the BP board until the end of November and has been put forward as a non-executive director of the firm’s TNK-BP Russian joint venture.

BP chairman Carl-Henric Svanberg said the firm was deeply saddened to lose a chief executive whose success was so widely and deservedly admired.

But he added that the Deepwater Horizon explosion, which left 11 workers dead, had been a “watershed incident”.

“It will be a different company going forward, requiring fresh leadership supported by robust governance and a very engaged board,” Mr Svanberg said.

Mr Hayward joined the company in 1982 and has been chief executive since 2007 – before the spill he had been credited with reviving its fortunes.

Yesterday, he said: “The Gulf of Mexico explosion was a terrible tragedy for which – as the man in charge of BP when it happened – I will always feel a deep responsibility, regardless of where blame is ultimately found to lie.

“BP will be a changed company as a result and it is right that it should embark on its next phase under new leadership.”