Tribune staff | Ryerson Inc. Chief Executive Stephen E. Makarewicz told its board of directors he plans to retire before the end of 2012 and the company announced Tuesday  it had begun a global search for his successor.

Makarewicz, 63, who has been CEO and president of the Chicago-based company since August 2008, said he plans to retire by age 65. He previously served as president of Ryerson South from June 2000 to October 2007 and was president, CEO and chief operating offer of J.M. Metals Co., Inc. from October 1994 until its January 2006 merger with Ryerson.