Milo Hamilton, who has served as the voice of the Astros for more than a quarter century, will announce during a press conference scheduled for Wednesday at Minute Maid Park that he plans to retire following the 2012 season.

The team acknowledged late Tuesday it was having a press conference for Hamilton, but it wouldn't comment on the nature of the announcement. A source confirmed for MLB.com the 84-year-old Hamilton will announce he is retiring after what will be 59 years announcing Major League games.

"Milo's had a brilliant, brilliant career and is one of the premier broadcasters in the history of Major League Baseball and has certainly put a lot of leadership and excitement into the Astros for the years he served," former Astros owner Drayton McLane said. "He's really been an important part of the franchise, and it's going to be unusual not to have him there doing his job he does in such a wonderful way."