The governor's office announced Friday that Robert Hallman stepped down on March 1. He was Cuomo's deputy secretary for energy and environment.
The Times Union of Albany, reports that Hallman had been a key player in the administration's deliberations over whether to allow a major expansion of natural gas drilling in the state.
No reason was given for his departure, but the governor's office said it was "amicable."
Hallman practiced law and was chairman of the New York League of Conservation Voters before joining the administration.
The gas industry has been pressing for permission to increase drilling in New York, as it has in neighboring Pennsylvania, but Cuomo has delayed exploration amid opposition from environmentalists.
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