The Amazon founder becomes executive chairman, a move he says will allow him to focus on other ventures.
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By Chris Fox
Technology reporter
By Natalie Sherman
Business reporter, New York
Who is Sundar Pichai and what does Alphabet do?
Copyright: AFPSundar Pichai, chief executive of Google, has been put in charge of its parent company Alphabet, after co-founders Larry Page and Sergey Brin announced they were stepping down.
The 47-year-old said the pair had set up a "strong foundation" on which he would "continue to build".
Pichai's life story is remarkable, and his rise to the top of Google is an endorsement of India's standing in the global technology industry - and equally, a reassuring reminder of the so-called "American Dream".
Pichai was born and schooled in Chennai, India. He captained his school's cricket team, leading it to win regional competitions.
From humble beginnings: Alphabet's new boss
Copyright: Getty ImagesWith the changes at the top of Google's parent company Alphabet, that means new boss Sundar Pichai becomes one of the most powerful people in the corporate world.
This profile by the BBC's Dave Lee in 2015 shows how Mr Pichai came from humble beginnings to assail the elite ranks of global technology.