By Della Hasselle
DNAinfo Reporter/Producer
MANHATTAN — Apple co-founder and chief executive Steve Jobs is taking a medical leave from work only a year and a half after his liver transplant, according to reports.
In a letter to employees, Jobs said Monday that the company's chief operating officer, Timothy Cook, will take over the company's daily maintenance.
Jobs added, however, that he would "continue as CEO and be involved in major strategic decisions for the company."
"I love Apple so much, and hope to be back as soon as I can," the letter continued.
The letter didn't specify the reason for the medical leave, and he asked for his and his family's privacy concerning the matter, the Associated Press reported.
Jobs has had a history of health issues. In 2004, he had surgery to recover from pancreatic cancer, and in 2009 he went on medical leave to secretly fly to Tennessee for a liver transplant, the New York Times reported.
A person familiar with his illness said that Jobs has a hormone imbalance common with people who have had liver transplants, according to the paper.
His health suffers from "ups and downs," according to a person who spoke in anonymity, and has caused Jobs to look increasingly thin, the Times reported.
Some shareholders have been critical of Jobs' decision to keep his health issues private, since Jobs is so linked to the Apple's progress. In the past year alone, he personally unveiled both the iPad and the iPhone4.
Some analysts are worried about whether Jobs will come back to Apple at all this time, and what it will do for the company if he doesn't. Apple's stock immediately dipped by six points in Germany after Jobs health news became public, the Times reported.
Short-term company projections look good, but long-term prospects are less certain, Neeham & Company analyst Charles Wolf told the Times.
"Right now Apple has a management team that is one of the greatest in American business," Wolf told the paper. "Whatever trajectory the company is on will continue for two to five years, regardless of whether Steve comes back."
