By Sara Sjolin, MarketWatch

LONDON (MarketWatch) -- The U.K. stock market ended in positive territory, spurred by optimism over better-than-expected data from the eurozone on Thursday.

Despite the upbeat sentiment, Tesco PLC shares slumped on Thursday after a profit update.

The FTSE 100 index rose 0.3% to 6,419.15, extending gains into a third straight day. The benchmark opened in negative territory, but tracked its European peers higher after data showed the eurozone manufacturing sector is expanding at a faster-than-expected pace in October.

Falling to the bottom of the London index, shares of Tesco (TSCDY) sank 6.6% after the supermarket chain said an investigation into its accounting practices showed the profit forecast for the first half had been overstated by 263 million pounds ($422 million). In September, the company said the accounting error was GBP250 million. Chairman Richard Broadbent will now step down, Tesco said.

Other supermarkets tracked Tesco lower, with shares of Wm Morrison Supermarkets PLC and J Sainsbury PLC down 3% and 1.8%, respectively

Shares of Unilever PLC (UL) dropped 3.7%. The maker of Magnum ice cream and Dove shampoo, among other things, said sales growth slowed in the third quarter and warned of a tough outlook.

Mining firms were also on the decline in London, as metals prices were mixed. Shares of Rio Tinto PLC (RIO) lost 0.9% and BHP Billiton PLC (BHP) fell 0.4%. Anglo American PLC gave up 1.2%, despite reporting a rise in iron-ore production.

On a more upbeat note, shares of GlaxoSmithKline PLC (GSK) rose 2.5% after Barclays lifted the drug maker to overweight from equal weight.

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