The European Union threatened to levy fines on Google Inc. that would be large enough to act as a deterrent after accusing the U.S. search-engine giant of squeezing out rivals in the comparison-shopping market. The EU’s competition watchdog told Google it could face a fine based on its AdWords revenue stemming from European users, according to a version of the statement of objections released to complainants and seen by Bloomberg. The EU also said it may tell Google to make changes to how its shopping services are displayed.