"We are concerned that exporting more LNG would lead to greater hydraulic fracturing, or fracking, activity thus threatening the health of local residents and jobs," the Platts news service quoted the letter as saying.
They said LNG exports could equate to about 30 percent of the national gas production and expressed concern that Chu hasn't announced plans for an environmental review.
"Such a review would inform your agency's decision and address the environmental and health impacts in our communities that may result from the opportunity to increase LNG exports," the letter read.
Environmental groups have called for similar restrictions on LNG. The chemicals used in hydraulic fracturing fluid are viewed as environmental threats.
Alaska is the only U.S. state that exports LNG. A facility in the state can process around 240 million cubic feet of gas per day. The Department of Energy said it has received applications from energy companies to export as much as 47 billion cubic feet of LNG per day.