Three years ago, liquefied natural gas turned up in a conversation concerning how Anadarko Petroleum Corp. ended up exploring for oil in Algeria. Trunkline, a sibling of the Houston independent, which was part of Panhandle Eastern at the time, had a long-term contract with Sonatrach for high-priced LNG in 1986, when gas prices had crashed. Panhandle was looking for ways to get out of the deal, or it would pummel the company. Eventually it was worked out that the newly spun-off Anadarko