CUPERTINO, Calif. - Steve Jobs, the co-founder and former CEO of Apple, died today at the age of 56.

"We are deeply saddened to announce that Steve Jobs passed away today," the company said in a brief statement.

"Steve's brilliance, passion and energy were the source of countless innovations that enrich and improve all of our lives. The world is immeasurably better because of Steve."

Jobs had battled cancer in 2004 and underwent a liver transplant in 2009. The company did not give a specific cause of death.

He took a number of leaves of absence from the company in recent years while dealing with health issues before resigning from the company in August. Tim Cook was announced as the company's new CEO to replace Jobs.

Jobs was best known for leading the company during the development of such product lines as the ubiquitous iPod, iPhone and iMac.

He had grown the company from a garage-based business founded with a friend in 1976 to the second-largest company in the U.S., even briefly surpassing Exxon-Mobil as the most valuable company in the U.S. this year.

Outside Apple's Cupertino headquarters, three flags - an American flag, a California state flag and an Apple flag - were flying at half-mast late Wednesday.

AP wire services contributed to the report.

Apple statement

White House statement

Key dates from the life and work of Steve Jobs