(For a Reuters live blog on U.S., UK and European stock markets, click LIVE/ or type LIVE/ in a news window) * FTSE 100 up 0.4%, FTSE 250 adds 0.4% April 28 (Reuters) - London’s FTSE 100 climbed on Wednesday, boosted by a series of positive earnings updates from companies, including Lloyds Banking Group and WPP, while investors awaited the outcome of the U.S. Federal Reserve’s policy meeting. The blue-chip index rose 0.4%, with Lloyds Banking Group jumping 3.7% after Britain’s biggest domestic bank reported upbeat profit for the first three months of the year. WPP gained 3.2% after the world’s biggest advertising company said its underlying net sales had returned to growth ahead of target as clients started to spend to prepare for the global economic recovery. Investors’ focus has now turned towards the U.S. central bank, which is expected later in the day to reaffirm that easy monetary policy will remain in place for a prolonged period and dismiss any suggestions of tapering bond purchases. The domestically focussed mid-cap FTSE 250 index advanced 0.4%.