U.S. Cash Grains-Corn firm on river, soy mixed

Nov 19 (Reuters) - Corn spot basis bids were firm at U.S. Midwest river terminals early on Tuesday, bolstered by lower barge freight rates and a drop in futures to fresh three-year lows that made the grain more competitive in global export markets, dealers said. * Soybean bids also firmed along the Illinois River, while[...]