OIL group Shell swept aside nearly 100 years of history yesterday when it announced plans to merge its UK and Dutch parent companies.

Shell said scrapping its twin-board structure was the best way of eliminating failings that led to the shock 20 per cent downgrade in its reserves earlier this year.

The move caught the City by surprise and came as Shell announced that net income more than doubled to £2.95bn in the third quarter.

After stripping out the cost of supplies, Shell made nearly £1.1m an hour - more than rival BP, which announced that it was making £1m an hour when it updated the market on Tuesday.

But joy at the profits performance and changes to corporate structure was tempered by a warning that its oil and gas reserves could be downgraded again.

Shell said another reclassification - its fifth this year - was likely, after auditors questioned the status of 900 million barrels of oil and gas stocks.

The changes announced yesterday will involve the transfer of more than 200 senior jobs across the North Sea, representing seven per cent of the 3,000 staff who work at its London headquarters. However, Shell said its global downstream and trading businesses would remain in the UK.