World shares are mixed and US futures edge higher, while oil prices slip

World shares were mixed on Friday following a retreat on Wall Street as a U.S. Treasury Department plan to boost its government debt buybacks appeared to have only limited capacity to calm markets. In early European trading, Britain's FTSE 100 slipped 0.1% to 10,737.04. In Asia, Japan’s Nikkei 225 fell 0.3% to 66,016.36.