Mumbai, Dec. 19 -- Natural Gas futures slumped yesterday, giving up heavily in intraday moves as markets eyed tepid demand outlook, cutting a rally towards $4 per mmbtu mark. The counter has yet again neared its two and half month low. Working natural gas in storage across the United States fell by 167 billion cubic feet in the week ending December 12 compared to the previous seven-day period to reach 3,579 billion cubic feet, the Energy Information Administration (EIA) said yesterday. Annually, the storage dropped by 1.73% though the stockpiles are up 0.90% compared to the five-year average of 3,547 billion cubic feet. The total working gas was within the five-year historical range. The counter has been enduring heavy losses after topping ...