.L Britain's biggest retailer Tesco TSCO.L dropped 4.7% after it warned profit was likely to fall in the current year. For a Reuters live blog on U.S., UK and European stock markets, click LIVE/ or type LIVE/ in a news window April 13 (Reuters) - European shares retreated for a third straight session on Wednesday as anxiety about elevated inflation and its potential impact on upcoming earnings season dampened risk appetite. Wall Street reversed early gains to end lower on Tuesday after data showed U.S. consumer prices rose to over four-decade highs in March.