Google founders Larry Page and Sergey Brin have announced they are stepping down from their top roles at Alphabet.

Page and Brin will leave their roles as CEO and president of Alphabet, respectively, but will continue their involvement as co-founders, shareholders and members of Alphabet’s board of directors.

They also maintain control of the parent company, with more than 51 per cent of the votes in Alphabet.

Sundar Pichai, CEO of Google, will take on the additional role of CEO at Alphabet. This includes taking over its portfolio of “other bets” – a collection of tech projects that include a research and development unit, renewable energy from wind using propellers on airborne kites, and healthcare company Calico.

The Stanford students founded Google in their garage back in 1998, and went on to become one of the most successful management double-acts in history.

John Hennessy, Chairman of Alphabet’s Board of Directors, said: “It’s impossible to overstate Larry and Sergey’s contributions over the past 21 years. I’m grateful that they will continue their involvement on the board.”

In 2015 the pair created Alphabet as part of a corporate restructuring of Google – appointing Pichai as Google’s CEO. The new structure was intended to make the tech giant's activities “cleaner and more accountable”, as it expanded from internet search into new experimental areas.

With the holding company now well-established, and Google and the other bets operating effectively as independent companies, Page and Brin said, it was a “natural time to simplify our management structure”.

“We’ve never been ones to hold on to management roles when we think there’s a better way to run the company,” the pair said.

Alphabet A shares rose 0.8 per cent in after-market trading to $1,304 following the announcement.

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