Atmos Energy Corp., the country's largest fully regulated, natural-gas-only distributor, has announced changes to its leadership team, effective Oct. 1.

The company's current President and COO Michael Haefner has been appointed as president and CEO, while current CEO Kim Cocklin has been appointed to the position of executive chairman of Atmos' board, according to an Aug. 2 news release.

The current chairman of the board, Robert Best, will continue to serve as a director after Oct. 1.