UPDATE 1-U.S. natgas futures fall to fresh 14-year low on weak heating demand

(Adds latest prices) Dec 16 (Reuters) - U.S. natural gas futures set a 14-year low on Wednesday on forecasts for continued unseasonably mild weather that should keep heating demand extraordinarily light through late December. The front-month January contract is testing the $1.76 support level, which was the 2001 low. If it falls below that, futures would drop to their lowest point since March 1999. Front-month natural gas futures on the New York Mercantile Exchange closed down 3.