European shares .STOXX slipped 0.3%, retreating further from almost three-week highs hit a day earlier, and London's FTSE slid as much as 1% even as data showed British inflation fell unexpectedly in August. In Asia, Japan's Nikkei .N225 tumbled 2.6% and MSCI's broadest index of Asia-Pacific shares outside Japan .MIAPJ0000PUS fell 2.2%. U.S. stock futures were mixed a day after the steepest fall on Wall Street in two years.