The state's revenue commissioner is resigning after just seven months on the job to take over as chief financial officer of a start-up renewable energy company.
Henry Dormitzer said Free Flow Power Corp. is run by a friend, who offered him the position.
"It's an idea I believe in," he said. "Renewable energy is what's happening right now. I came from the private sector. I like the idea of building a business."
His resignation is effective at the end of the month.
Deputy Revenue commissioner Navjeet Bal will be promoted to commissioner by Governor Deval Patrick's administration.
Dormitzer was appointed in June to replace Alan LeBovidge, who held the post for five years.
Dormitzer spent most of his career in the private sector.
Bal has been senior deputy commissioner since September, after she worked more than 17 years for a law firm in Boston.