Tesco PLC, Britain's largest supermarket operator, has reported a 12 percent fall in half yearly pre-tax profit to 1.7 billion pounds ($2.7 billion), as a downturn in Asia and Europe offset stronger sales in Britain.

Tesco also said Wednesday that net profit in the six months to Aug. 25 fell to 1.28 billion pounds from 1.38 billion pounds.

Group sales were up 1.4 percent to 36 billion pounds in the half-year period, while sales in Britain rose 2.2 percent to 23.9 billion pounds.

Chief executive Philip Clarke said Tesco's decision to invest 1 billion pounds in sprucing up its U.K. stores was paying off, but added there is "much more to be done."

Tesco shares fell 1.2 percent to 3.33 pounds in early trading on the London Stock Exchange.