An increase in exports of domestic liquefied natural gas could raise gas prices in the United States by as much as 54 percent by 2018, a new government report says.

The report, released by the Energy Information Administration, lays out four scenarios of export-related increases in natural gas demand. The U.S. Department of Energy requested the study to assess how natural gas exports would affect the country's energy markets.

"Larger export levels lead to larger domestic price increases, while rapid increases in export levels lead to large initial price increases that moderate somewhat in a few years," the report states.

U.S. Rep. Ed Markey, D-Mass., the ranking member of the House Natural Resources Committee and a senior member of the Energy and Commerce Committee, in response to the EIA report urged the Energy Department to halt the certification of any more export projects "before all impacts on American families and businesses are considered."

Nine companies are awaiting federal approval to export about 10 billion cubic feet of LNG per day.

Those proposals, along with Cheniere Energy's already approved plan to export more than 2 billion cubic feet daily from its Sabine Pass LNG terminal in Louisiana, represents about 14 percent of the natural gas produced in the United States , the Houston Chronicle reports.

"The affordable domestic supplies we've recently developed could soon become a thing of the past if companies are allowed to export large volumes of American natural gas supplies to foreign countries," Markey said in a statement.

He said he plans to introduce legislation that would keep more American-made natural gas in the country.

Domestically, the price of natural gas has dropped to less than $3 per million British thermal units, from more than $15 a few years ago, as technology has made it economical to extract natural gas from dense shale rock.

But in Europe, natural gas is selling for as much as $12 per million British thermal units, and as high as $18 in some Asian markets, Ira Joseph, executive director for international gas at consulting firm PIRA Energy Group told the Chronicle.

EIA acknowledged that projections of energy markets over a 25-year period "are highly uncertain and subject to many events that cannot be foreseen, such as supply disruptions, policy changes, and technological breakthroughs."

Still, EIA says that an increase in natural gas exports would lead to higher domestic natural gas prices, increased gas production, reduced domestic consumption and higher imports from Canada.