Apple Inc. Chief Executive Steve Jobs is taking a second medical leave -- the first was two years ago when he underwent a liver transplant during a six-month hiatus -- and the news sent the company's high-flying stock into a dive in overseas trading.
Jobs, who previously battled pancreatic cancer, has again handed Chief Operating Officer Tim Cook the day-to-day reins at Apple. The news sent Apple shares down 7.6% in trading in Frankfurt. Monday was a holiday in the United States, and the markets were closed there.
Jobs, who co-founded Apple in 1976, said in a memo to staff that he would continue to be Apple's CEO and would take part in major strategic decisions.
"At my request, the board of directors has granted me a medical leave of absence so I can focus on my health," Jobs, 55, wrote. "I love Apple so much and hope to be back as soon as I can."
This is the third time in the last decade that Jobs has reduced his role at Apple because of his health. He also took medical leave in 2004.
Jobs is critical to Apple. He is deeply enmeshed in the company's business, making key product decisions. The chief executive is inextricably linked to the company, credited with reviving its flagging fortunes in 1996 when he returned after a 12-year hiatus. He oversaw hit products such as the iMac and, more recently, the iPod, iPhone and iPad.
The announcement came as a surprise and was bound to rattle investors who attribute Apple's soaring success as a consumer-electronics giant to Jobs. His absence will not be a major concern with such strong momentum and product line in the pipeline for the next few years, but if the absence is prolonged, it could deflate the stock. Apple is set to report quarterly earnings on Tuesday.
Investors also have had confidence in the past in the stewardship of Cook, 50, known as the executive who makes Apple's trains run efficiently and on time. Cook joined Apple in 1998 and stepped in for Jobs during both of his leaves of absence.
Questions about Jobs' health have peppered the company for years, with some analysts and investors criticizing Apple for not making more information available.
An Apple spokesman declined to comment.
[Updated, 8:30 a.m.: Another major concern: the lack of succession planning at Apple, said IDC analyst Al Hilwa.
"Obviously the company is a lot more than Steve Jobs; it's a sizable franchise that can go on without him for a while," Hilwa said. "But the company still very much revolves around Steve Jobs, and we are going to see some fall back from that in the stock market. They will have to show several quarters of execution without him to comfort the market that they can do all right without him. He has been involved in such detailed work in everything at the company, you really wonder how they can get by and make decisions without him."
The Wall Street Journal reported the news earlier.]
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Photo: Apple Chief Executive Steve Jobs on June 7, 2010. Credit: Paul Sakuma / Associated Press
Jobs en junio de 2010.

 Steve Jobs, el CEO de Apple Inc., anunció este lunes en un memo interno que tomaría licencia por enfermedad por una duración indefinida. La noticia causó una fuerte baja en el precio de las acciones de Apple en los mercados extranjeros; las bolsas de Estados Unidos no operaron en honor a Martin Luther King.

El anuncio marca la tercera vez en una década entera en que Jobs, de 55 años de edad, toma una licencia por enfermedad. Había luchado contra un cáncer pancreático en 2004, y tomó seis meses de licencia en 2009, por motivo de un trasplante hepático.

Jobs aún no ha revelado por qué tomó esta decisión, pero declaró que seguiría siendo el CEO de la compañía. Mientras tanto, dejó a Timothy D. Cook, oficial operador en jefe, a cargo de las operaciones del día a día, la misma decisión que fue tomada en 2004 y 2009.

Apple no ha hecho ningún otro comentario adicional, pero ''The New York Times'' reportó que alguien familiar a la situación dijo que la salud de Jobs tiene "altibajos" debido a deficiencias de su sistema inmune, una complicación usual en personas que atravesaron un trasplante hepático.

La fuente, que pidió permanecer anónima, reveló que durante las últimas semanas la salud de Jobs se ha deteriorado y que ha perdido peso. Lewis W. Teperman, un doctor de la Universidad de Nueva York, declaró que es "muy común para pacientes que recibieron trasplantes que tengan problemas que no-riesgosos".

En su sitio web, Apple publicó el texto del e-mail enviado por Jobs: