GLOBAL MARKETS-Shares gain in broad global advance, U.S. debt prices fall

* Dow hits record high, S&P nears new record * Crude oil up on rising Ukraine tensions * Euro comes under pressure after ECB comments * U.S. debt prices fall before heavy week of data (Adds opening of U.S. markets; changes dateline; previous LONDON) By Herbert Lash NEW YORK, May 12 (Reuters) - Global equity markets surged on Monday, with the Dow industrials setting a record high as stocks advanced in a broad rally spurred by strong corporate results and an improving economi