Under the re-branding, Google will retain its best-known businesses, such as search, apps, YouTube and Android.

Some of the newer entities, such as the investment and research divisions, the "smart-home" unit Nest, and the drone arm will be run under Alphabet.

Google founder Larry Page said it would create a simpler structure for what had become a diverse group of businesses.

"This new structure will allow us to keep tremendous focus on the extraordinary opportunities we have inside of Google," he said in the blogpost.

"Our company is operating well today, but we think we can make it cleaner and more accountable," he said.

Mr Page will become chief executive of Alphabet, with senior vice president Sundar Pichai becoming CEO of Google.

Mr Page's fellow Google co-founder Sergey Brin will become president of Alphabet, and Eric Schmidt, the current Google chairman, will be executive chairman of the holding company.