Lawmakers last weekend backed a ban on drilling in shale plays in Bucks and Montgomery counties until such time that the state's Department of Conservation and Natural Resources can complete a five-year study of the region.
Lou D'Amico, director of the Pennsylvania Oil and Gas Association, was quoted by the Platts news service as saying the decision set a bad example.
"If I were an oil company and saw that kind of legislative activity, I would think long and hard before making any kind of investment in any kind of property in southeastern Pennsylvania," he said.
Pennsylvania hosts part of the Marcellus shale play, one of the richer sources of shale gas in the United States.
Trade group Marcellus Shale Coalition said in June access to shale in the state is "yet one more way that the development of Pennsylvania's natural resources are benefiting the commonwealth and our nation."
The U.S. Geological Survey in June said gas reserves in the region could hold as much as 876 billion cubic feet of natural gas.