Brent North Sea crude oil for September delivery rose 55 cents to 40.25 dollars a barrel in the first few minutes of trading in London.

The contract had tumbled by 94 cents on Wednesday, just hours after setting a record of 40.99 dollars a barrel.

New York's benchmark contract, light sweet crude for delivery in September, climbed 40 cents to 43.23 dollars in pre-opening electronic deals Thursday.

The contract plunged 1.32 dollars on Wednesday, having earlier hit an all-time high 44.34 dollars.

But analysts warned the respite could prove shortlived.

"Onwards and upwards as oil prices head towards 50 dollars," analysts at Barclays Capital told clients.

"The market continues to be dominated by the potential for a severe supply crunch as global oil demand swings up towards its seasonal peak," they added.

Prices had dived on Wednesday after Russian Justice Ministry officials said Yukos could use previously frozen bank accounts to keep running on a daily basis and pay off back taxes.

And the Organization of Petroleum Exporting Countries said that it had surplus production capacity of up to 1.5 million barrels per day (bpd) immediately available.

"OPEC continues to hold, at present, a spare production capacity of around 1-1.5 million bpd, which would allow for an immediate additional increase in production," the OPECNA news service quoted OPEC President Purnomo Yusgiantoro as saying in a statement.