* Corn falls 2 pct, soy dips from 4-month top * Planting pace seen slowest since 1996 * Warmer forecast enhances crop growing conditions * Grain markets eye June 12 USDA monthly forecasts (Updates prices, adds analyst quotes) By Michael Hirtzer CHICAGO, June 10 (Reuters) - U.S. corn futures plunged 2 percent on Monday, the