SAN FRANCISCO: The first person hired by Google's founders is leaving the Internet giant to devote himself to an innovative online education website called Khan Academy.

Google on Thursday confirmed that Craig Silverstein is departing the California company he helped Larry Page and Sergey Brin build into the world's most popular search engine.

"Craig's been with Google since the early days," Google said in an emailed response to an AFP inquiry.

"He was instrumental in the development of search and made numerous contributions to Google over the years.

"We wish him all the best at the Khan academy and know that he will do great things to help them promote education around the world," Google said.

Silverstein was "Googler number 3," joining graduate students Brin and Page about 14 years ago after they launched the service in a Stanford University dorm room.

The engineer planned to join Salman Khan at the nonprofit Khan Academy, which provides online video classes. Google and the Bill and Melinda Gates Foundation are listed among the academy backers.