Rodney Waller, a senior vice president at the oil and gas company Range Resources, called the expected surge in liquefied natural gas imports part of a “pile on” of problems including plummeting demand, prices and credit besetting companies that stretched their exploration and production budgets in recent years to meet expanding demand.

“Any time you push the price down, you push down the ability of U.S. independents to add reserves and production domestically,” he said. He warned that some small and midsize oil and gas companies “with debt that are in trouble now will simply get pushed over the brink.”

Natural gas is becoming a world commodity like oil. It is still loosely connected to world oil benchmark prices and its price, usually set by longer-term contracts everywhere except for the United States and Britain, can diverge widely from one continent to another. Until the last few years, liquefied natural gas was a high-priced necessity for countries that did not produce their own gas supplies or have access to piped reserves; but it now has become a cheap economic driver for countries like Japan with few energy resources.

But as more terminals have been built, the amount of gas that is shipped from one continent to another in giant tankers has climbed. And now the emergence of the global market in gas is about to take a giant leap.

The global capacity for liquefied natural gas exports of 200 million tons a year will increase by 25 percent with the completion of six new plants in Qatar, Russia, Indonesia and Yemen, totaling $48 billion in investments, and the upgrading of a seventh plant in Malaysia. National energy companies in those countries, assisted by ExxonMobil, Total, BP and Shell, rushed construction of those projects in recent years to satisfy the mushrooming appetite for energy around the world. More large plants are due on line in 2010 and 2011.

“We had many years of ever increasing demand so the world geared up for that, but what the world did not prepare for was an economic recession that is global in scope and in impact,” said Darcel L. Hulse, president and chief executive officer of Sempra LNG, a division of Sempra Energy that operates an import terminal in Mexico and is completing construction on a facility in Louisiana. “That is what has exacerbated the imbalance of supply and demand to such an excess.”