Major League Baseball commissioner Bud Selig says that he is "firm" about leaving office when his current term expires after the 2012 season. Selig has changed his mind in the past and accepted extensions from team owners, but said this time he plans to exit when his contract is up. "I feel firm about it," Selig said. "This will be 20 years (in office). That's a long time in this job. I'm going to be 78 (next year). I have begun teaching and there are other things I want to do, including writing a book. I'm looking forward to it. I'm comfortable with that."