GLOBAL MARKETS-Stocks slip after hitting multi-year highs

* Upbeat global economic data supports world shares, oil * Euro, bonds steady as Spanish bond auction eyed. * UK central bank seen leaving policy unchanged By Richard Hubbard LONDON, May 9 (Reuters) - Ongoing support from easy central bank monetary policies underpinned global stocks on Thursday although profit-taking pushed European and Japanese shares off multi-year highs. In early European trading the blue chip Euro STOXX 50 , Britain's FTSE 100, Germany's DAX and France'