The UK's leading grocer said like-for-like sales - which strip out the effect of new store openings - rose 6.9% in the 14 weeks to mid-November.

The figure beat analysts' forecasts, and compared with flat sales growth from rivals Sainsbury and Safeway in the three months to mid-September.

Tesco said the rise partly reflected strong growth in non-food sales.

Global strength

It added that its overseas stores - spread across eastern Europe and south-east Asia - had also performed well, with sales up by 31%.

"This is stronger than we were expecting, and I think stronger than anyone was expecting," said Mark Hughes at Numis Securities.

Most analysts had predicted like-for-like sales growth of between 4% and 6.2%.

However, Tesco said it expected sales growth to moderate in the months ahead.

"We would expect a return to more normal levels of trading in the future," Tesco finance chief Andrew Higginson told Reuters.

Stiff competition

Tesco's latest sales numbers confirm its pre-eminent position in the UK grocery sector, with its share of the market now estimated at 27%.

They will make grim reading for third-ranked Sainsbury, which lost the number two spot to Asda earlier this year, and is struggling to deliver sales growth despite an expensive store refurbishment programme.

Sainsbury and Asda face a fresh competitive challenge from Bradford-based Morrison's, which in September won regulatory approval to launch a takeover of fourth-ranked Safeway.

The other three major supermarket chains - which had also expressed an interest in buying Safeway - were barred from bidding on competition grounds.

However, the three firms are in the running to buy 53 Safeway stores that Morrison must sell as a condition of its takeover going ahead.