SPRINGFIELD, Ill. (AP) — Illinois Republican state Sen. Matt Murphy is resigning his seat to take a job in the private sector.

Murphy is one of GOP’s top lawmakers in the Senate and has been one of the lead voices in budgetary issues as well as one of the governor’s biggest allies.

The suburban Chicago lawmaker said in a letter Friday that his resignation is effective Sept. 15.

Murphy said in the letter the job he is taking “allows me to better meet my family obligations” but did not specify where he is going. He thanked his constituents for “giving me the chance to live out this dream.”

Republican Gov. Bruce Rauner says he was surprised and disappointed by Murphy’s announcement and called him a great legislator who will be missed.