Co-founders of Google, Larry Page and Sergey Brin, have stepped down as CEO and President of its parent company, Alphabet.

A joint letter from founders Larry Page and Sergey Brin explained that Google CEO, Sundar Pichai, would take charge of Alphabet.

“Going forward, Sundar will be the CEO of both Google and Alphabet,” the letter said.

“He will be the executive responsible and accountable for leading Google, and managing Alphabet’s investment in our portfolio of Other Bets.”

‘Other Bets’ refer to the hundreds of acquisitions made by Google and Alphabet over the past two decades.

Founded by Brin and Page, 1998, Google company started as a research project between the pair while they were PhD students at Stanford University.

It went public in 2004 at a price of US$85 per share, raising US$1.6 billion. Now, shares in Alphabet trade at around US$1,300 and the company has a market capitalisation of US$900 billion.

While Brin and Page are stepping down as CEO and President of Alphabet, the pair affirmed they would continue to have input in the company’s direction, and control 56 per cent of the stockholder voting power.

“We are deeply committed to Google and Alphabet for the long term, and will remain actively involved as board members, shareholders and co-founders,” Brin and Page said.

“We are deeply humbled to have seen a small research project develop into a source of knowledge and empowerment for billions—a bet we made as two Stanford students that led to a multitude of other technology bets.

“We could not have imagined, back in 1998 when we moved our servers from a dorm room to a garage, the journey that would follow.”

Twenty-one years after moving their servers into a Californian garage, Alphabet is one of the biggest companies in the world.

Google is the most visited website in the world, its Android operating system is the world’s most popular mobile OS, and Google researchers are leading the way in quantum computing.

Alphabet’s new CEO is a familiar face for Googlers.

During Google’s 2015 restructure, Sundar Pichai became CEO of Google.

Born in Chennai, India, Pichai won a scholarship to Stanford – alma mater of Brin and Page – where he completed his masters.

Pichai started off by working on Google’s search toolbar and has since risen through the ranks of the tech giant and maintained a public-facing role – like when he announced how Google Assistant can make phone calls on your behalf.

“I’m excited about Alphabet and its long term focus on tackling big challenges through technology,” Pichai said.

“I’m looking forward to continuing to work with Larry and Sergey in our new roles.

“Thanks to them, we have a timeless mission, enduring values, and a culture of collaboration and exploration.

“It’s a strong foundation on which we will continue to build.”