** Shares of U.S. natural gas companies rise, tracking increase in natgas futures NGA
** U.S. natgas futures NGc1 up 4% at $4.15 per million British thermal units
** Natgas prices supported by expectations of higher demand due to colder weather and record gas flows to LPG export plants
** Natgas companies: CNX Resources CNX.N up 1.1%, Expand Energy EXE.O up 1%
** Natgas ETFs: United States Natural Gas Fund UNG.P and ProShares Ultra Bloomberg Natural Gas BOIL.P advance 4% each
(Reporting by Dharna Bafna)
((Dharna.bafna@thomsonreuters.com))