Steve Jobs, the charismatic chief executive of Apple Computer Inc. and Pixar Animation Studios, said Sunday he had surgery to remove a cancerous tumor from his pancreas but added that he expects a full recovery.

In an e-mail message to employees, Jobs, 49, said he will be off to recuperate during August and expects to return to work in September.

He identified his cancer as an islet cell neuroendocrine tumor, which he described as rare. Jobs said that it could be cured by surgical removal if diagnosed early; he said that his was caught early.

A far more deadly -- and common -- form of pancreatic cancer is adenocarcinoma, he said.

"I mention this because when one hears 'pancreatic cancer' (or Googles it), one immediately encounters this far more common and deadly form, which, thank God, is not what I had," he said in the message.

During Jobs's absence, Apple will be run by Timothy Cook, the company's executive vice president of worldwide sales and operations.

Jobs and friend Steve Wozniak founded Apple Computer in 1976, five years before IBM Corp. jumped into the personal computer market.

In 1984, the company released the Macintosh, which was the first commercially successful computer to have a graphical user interface that mimicked a physical desktop. It was eventually copied by makers of IBM-clone computers.

Jobs made a splash in 1998 with the release of a revamped and stylish iMac, which was followed by new lines of laptops as well as professional-grade computers and servers. In 2001, Apple jumped into the digital music player business with its iPod, which is now the most popular.

Last year, Apple launched the iTunes Music Store, which allowed legal music downloads after Jobs convinced music companies that his technology was secure.

Jobs is also CEO of Pixar Animation Studios, which produced "Finding Nemo" and "Toy Story."