NEW YORK, June 24 (Reuters) - Coal prices may remain weak in the near term as mining costs eat into margins, but world coal markets are set to boom again after the economic downturn, with developing countries in Asia dominating, a senior U.S. coal executive said on Wednesday.

Rick Navarre, president of Peabody Energy (BTU.N), said U.S. markets, where miners have sharply cut back production, will lag the Pacific region, but that the worst of the economic downturn "appears to be behind us."

"Global energy needs have been masked by the recession," he told the McCloskey Group coal conference in New York. "Markets are ultimately likely to rebound with a roar.

"Global demand will ripple back to the U.S., but that recovery is likely to lag as we work through inventories and other near-term challenges."

Stockpiles of coal at U.S. power stations are at their highest levels since the 1980s, Navarre said.

"Current spot prices are not sustainable, based on our knowledge of mining costs," he said.

According to the coal industry newsletter Coal & Energy Price Report, a short ton of Appalachian coal that cost $112.88 last September, is now selling for $47.14.

The downturn had resulted in near-term pain, Navarre said, as demand for electricity and steel -- both produced by coal -- had slumped around the world.

But he predicted a sharp rebound as industry gets back on its feet and new U.S. power plants add to coal demand.

"The Asia-Pacific region will dominate global supply and demand as urbanization, electrification and energy security needs drive long-term growth," he said.

Navarre said St. Louis-based Peabody, which operates mines in the United States and Australia and exports much of its coal to Asia, expects China and India to account for half of the growth in global coal demand over the next five years.

Seaborne demand, he said, is expected to grow by 150 million tonnes per year by 2013. In addition, another 200 gigawatts of new power generation is under construction and will come on line, representing an extra 700 million tonnes of coal demand. (Editing by Walter Bagley)