Natgas companies gain on lower output

** Shares of U.S. natural gas companies gain, tracking rise in natgas futures NGA/

** U.S. natgas futures NGc1 up 1.5% at $3.13 per million British thermal unit on recent declines in daily output

** Financial firm LSEG said average gas output in the Lower 48 states fell to 107.5 billion cubic feet per day so far in September, down from a record monthly high of 108.3 bcfd in August

** Shares of natgas companies: CNX Resources CNX.N and Cheniere Energy LNG.N up 1.5% each, Williams Companies WMB.N rise ~2% and Energy Transfer ET.N up marginally

** ETFs United States Natural Gas Fund UNG.P up 1.4% and ProShares Ultra Bloomberg Natural Gas BOIL.P gains 1.5%