Apple's legendary co-founder and top ideas man Steve Jobs resigned as chief executive Wednesday, the company said, in a long expected move after he began a dramatic fight with cancer. In a written statement, Apple, the world's second biggest company by market capitalization, announced that chief operating officer Tim Cook would take over as CEO but that Jobs would stay on as chairman of the board. "Steve's extraordinary vision and leadership saved Apple and guided it to its position as the world's most innovative and valuable technology company," board member Art Levinson said in a statement. No reason was given for Job's resignation, but his health problems, including a lengthy medical leave for a liver transplant in 2009 and his increasingly gaunt appearances at public events, fueled speculation he would have to give up the everyday running of the company he co-founded in 1976. Cook ran Apple when Jobs went on medical leave and has essentially been running day-to-day operations since early this year with the company racking up record revenue and profit. Jobs is seen as the heart and soul of Apple, with analysts and investors repeatedly expressing concern over how the Cupertino, California-based company would handle his departure. "The board has complete confidence that Tim is the right person to be our next CEO," Levinson said. "Tim's 13 years of service to Apple have been marked by outstanding performance, and he has demonstrated remarkable talent and sound judgment in everything he does," Levinson continued. Jobs submitted his resignation on Wednesday and urged the board to implement its succession plan and name Cook as his replacement, according to Apple. Cook was previously responsible for Apple's worldwide sales and operations, including management of the supply chain, sales activities, and service and support in all markets and countries. Jobs is a living legend in Silicon Valley. He is the beloved visionary behind the Macintosh computer, the iPod, the iPhone and the iPad. Born on February 24, 1955 in San Francisco to a single mother and adopted by a couple in nearby Mountain View at barely a week old, he grew up among the orchards that would one day become the technology hub known as Silicon Valley. Jobs was 21 and Steve Wozniak 26 when they founded Apple Computer in the garage of Jobs's family home in 1976. While Microsoft licensed its software to computer makers that cranked out machines priced for the masses, Apple kept its technology private and catered to people willing to pay for superior performance and design. Under Jobs, the company introduced its first Apple computers and then the Macintosh, which became wildly popular in the 1980s. Apple's innovations include the "computer mouse" to make it easy for users to activate programs or open files. Jobs was elevated to idol status by ranks of Macintosh computer devotees, many of whom saw themselves as a sort of rebel alliance opposing the powerful empire Microsoft built with its ubiquitous Windows operating systems. Jobs left Apple in 1985 after an internal power struggle and started NeXT Computer company specializing in sophisticated workstations for businesses. He co-founded Academy-Award-winning Pixar in 1986 from a former Lucasfilm computer graphics unit that he reportedly bought from movie industry titan George Lucas for $10 million. Apple's luster faded after Jobs left the company, but they reconciled in 1996 with Apple buying NeXT for 429 million dollars and Jobs ascending once again to the Apple throne. Since then, Apple has gone from strength to strength as Jobs revamped the Macintosh line, revolutionizing modern culture with the introductions of the iPod, iPhone, iPad, and iTunes online shop for digital content.