SAN FRANCISCO, Dec. 3 (Xinhua) -- Google Inc. co-founders Larry Page and Sergey Brin announced on Wednesday that they are stepping down as the chief executive officer (CEO) and president, respectively, of Google's parent company Alphabet.

The two men said in a joint letter published Wednesday that they are relinquishing the reign of Alphabet and handing it over to incumbent Google CEO Sundar Pichai, but will both remain on the board of Alphabet.

"With Alphabet now well established, and Google and the Other Bets operating effectively as independent companies, it's the natural time to simplify our management structure," they said.

Page and Brin noted that Pichai will be responsible and accountable for leading Google and managing Alphabet's investment, but they will remain "actively involved as Board members, shareholders and co-founders."

Page and Brin were among the founders who created Google in a Stanford University garage in California in 1998 and oversaw the company grow into an almost trillion-U.S.-dollar empire in the following 20 years.

After the restructuring of Google and creation of Alphabet in 2015, the pair moved to Alphabet to focus on the company's research projects and Other Bets, an arm of the company which focuses on side businesses such as internet provider Google Fiber and smart home brand Nest.

In an email to all employees at Google, which was made public on the same day, Pichai said the resignation of Page and Brin "won't affect the Alphabet structure or the work we do day to day."