Shares of Apple (AAPL) were halted for nearly 60 minutes following an announcement that CEO Steve Jobs will be taking a medical leave of absence.

JOBS NOTES HEALTH ISSUES MORE COMPLEX THAN THOUGHT, WILL TAKE MEDICAL LEAVE OF ABSENCE UNTIL JUNE
—Tim Cook, COO, will take over until Jobs returns

— Jobs’ Memo: ” I am sure all of you saw my letter last week sharing something very personal with the Apple community. Unfortunately, the curiosity over my personal health continues to be a distraction not only for me and my family, but everyone else at Apple as well. In addition, during the past week I have learned that my health-related issues are more complex than I originally thought.
In order to take myself out of the limelight and focus on my health, and to allow everyone at Apple to focus on delivering extraordinary products, I have decided to take a medical leave of absence until the end of June. I have asked Tim Cook to be responsible for Apple’’s day to day operations, and I know he and the rest of the executive management team will do a great job. As CEO, I plan to remain involved in major strategic decisions while I am out. Our board of directors fully supports this plan.”

I’ll provide additional commentary on this news in my wrap up tonight.