Opec’s grim forecast for summer oil prices comes as calls mount for the group to increase oil production and help reduce soaring fuel inflation.

And BP chief executive Tony Hayward warned against hopes that the present high priced are a bubble that will burst as they did in the 1970s, saying that supply and demand had since changed.

Energy-sensitive stocks lost value yesterday with British Airways, closing down 3.6%, following a general downward trend for European airlines. BP and Royal Dutch Shell were down 13.75p at 569.5p and 39p at 1981p respectively.

The price of oil and continuing credit problems have worried investors, who are unable to see an end in sight.

Yesterday European bank stocks fell to their lowest level for five years as banks continue to announce writedowns, falling profits and the need for more fundraising.

At one stage Swiss bank UBS had fallen more than 6% to its lowest level for a decade amid speculation that it is to announce writedowns, possibly of $5bn. It has already been forced to writedown $37bn since the sub-prime crisis broke last summer.

But it is the American banks who remain amongst the worst-hit, with investment bank Lehman Brothers shares losing 10% on Monday on the back of rumours it may be sold for a knock-down price.

Banks in Britain also had a rough day, as Royal Bank of Scotland fell more than 5% and Barclays and Lloyds TSB both fell more than 3%.

This was in part because of Nationwide’s house price survey which showed a 0.9% fall in prices, the eighth consecutive monthly decline.