UNITED STATES – Google co-founders Larry Page and Sergey Brin are stepping aside as leaders of the Internet behemoth they founded 21 years ago, ending an extraordinary run that saw them build one of the world’s most valuable and influential companies.

Reuters reports that Sundar Pichai, a Trusted lieutenant who run the core Google search business since 2015, will immediately take the reins as CEO of parent Alphabet Inc.

“While it has been a tremendous privilege to be deeply involved in the day-to-day management of the company for so long, we believe it’s time to assume the role of proud parents — offering advice and love, but not daily nagging!” Page and Brin wrote in a blog.

Page, Brin and Pichai have shared an emphasis on developing artificial intelligence software to make web searching faster and more personalized, while expanding the range of information and services available from a simple text query.

But their vision faces unprecedented scrutiny, with governments on five continents demanding better safeguards, an end to what many view as anticompetitive conduct, and more taxes from the world’s largest online advertising company.

Caughey Forrest, chief investment officer at Bokeh Capital Partners opined that, “This signals a shift away from the fringier efforts … and more towards a company focused on technology that makes money.”

Alphabet, which owns more than a dozen companies including self-driving car business Waymo and health care software company Verily, was created in 2015 as part of a restructuring.

The Google unit which has been headed by Pichai for the past four years, retained control of major businesses including video giant YouTube, the Android smartphone software and hardware operations, and cloud computing.

Page had wanted to focus on developing the newer businesses, which collectively lose money, leaving Google, by far the biggest and most profitable part of Alphabet, to Pichai, who in turn delegates a lot of authority to deputies who manage the various product lines.

Brin had stayed on as Alphabet’s president, spending time on robotics, health ventures and other research projects.

Page and Brin, both 46, remain directors of the parent company but will cede their respective CEO and president titles immediately, Alphabet said.

The president role will not be filled, it said, describing the changes as long discussed.

 The co-founders still control the company through their ownership of preferred shares.

As of April, Page held 26.1% of Alphabet’s total voting power, Brin 25.25% and Pichai less than 1%. Alphabet shares rose 0.56% following the after-hours announcement to $1,302.