The former State Representative announced he's leaving his post through a statement saying, "After giving the matter long and serious thought, I have informed my good friend Governor Quinn that I will be retiring from state government effective March 31," according to Springfield's State-Journal Register.
Hannig, a downstate Litchfield resident, was named by Gov. Pat Quinn in February 2009. He recently was appointed to another two-year term.
Hannig, 58, cites personal and family reasons for leaving, saying, "It is time for me to move on to another phase in my life."
He previously had been a member of the Illinois House since 1979.