By Nicole Friedman NEW YORK–Natural-gas prices gained for a third straight session on Tuesday but held below $4 a million British thermal units, as traders began looking ahead to expected winter demand. Natural gas for October delivery settled up 6.4 cents, or 1.6%, at $3.995/mmBtu on the New York Mercantile Exchange, the highest settlement since Aug. 29. Futures traded down earlier in the session on expectations that demand for natural gas would be muted in the next two weeks due to moderate temperatures. Natural-gas demand is most active during extreme temperatures, when people use gas-powered air-conditioning or turn on natural-gas indoor heating. Temperatures are expected to be cooler than normal in the eastern U.S. and hotter than average in the West in the next two weeks. However, traders who had bet on lower prices likely closed out those positions once prices fell near $3.86/mmBtu in intraday trading, allowing buyers […]