The Silicon valley group joins Apple, which first reached $1 trillion in 2018 and on Thursday showed a valuation of some $1.38 trillion; and Microsoft, now valued at some $1.26 trillion.

Another tech titan, Amazon, rose above the trillion-dollar mark in September 2018 but has since declined to a value of around $930 billion.

Google is the leading online search engine and produced the popular Android mobile operating system.

Alphabet, formed as a holding company in 2015, has a number of other units working on "moonshot" projects including Waymo on autonomous cars and Verily for life sciences.

The company announced last year that Google chief executive Sundar Pichai would also assume the CEO functions at Alphabet, raising speculation on whether a fresh reorganization is planned.

Pichai's promotion enabled Google co-founders Larry Page and Sergey Brin to step away from daily operations at the company.

-AFP