Considered as a significant shakeup in the Silicon Valley company, an announcement in this regard was made by Page and Brin in a letter to the company employees, which also included a statement from Pichai.
With Alphabet now well-established, and Google and 'Other Bets' operating effectively as independent companies, it's the natural time to simplify our management structure, wrote the two Google co-founders.
"We've never been ones to hold on to management roles when we think there's a better way to run the company," they said.
"And Alphabet and Google no longer need two CEOs and a President. Going forward, Sundar will be the CEO of both Google and Alphabet. He will be the executive responsible and accountable for leading Google, and managing Alphabet's investment in our portfolio of Other Bets," said Page and Brin.
"We are deeply committed to Google and Alphabet for the long term, and will remain actively involved as Board members, shareholders and co-founders. In addition, we plan to continue talking with Sundar regularly, especially on topics we're passionate about!" they wrote.
In his statement, Pichai made it clear that the transition will not affect the Alphabet structure or the work they do day to day.
"I will continue to be very focused on Google and the deep work we're doing to push the boundaries of computing and build a more helpful Google for everyone," he wrote.
"At the same time, I'm excited about Alphabet and its long term focus on tackling big challenges through technology," he said in his email.
Endorsing the leadership role played by Pichai ever since he was made Google CEO, Page and Sergey said the Indian-American brings humility and a deep passion for technology to their users, partners, and employees every day.
"He's worked closely with us for 15 years, through the formation of Alphabet, as CEO of Google, and a member of the Alphabet Board of Directors. He shares our confidence in the value of the Alphabet structure, and the ability it provides us to tackle big challenges through technology," they wrote.
"There is no one that we have relied on more since Alphabet was founded, and no better person to lead Google and Alphabet into the future," they said.