Google parent firm Alphabet is now worth some USD1 trillion based on its stock market value, becoming the fourth tech firm to reach that milestone. [AFP/File / DENIS CHARLET]

Google's parent company Alphabet saw its value reach USD1 trillion (Sh100tr) for the first time Thursday, becoming the fourth US tech company to hit the milestone.

Shares in the online giant rose 0.76 percent for the day to reach the trillion-dollar mark at the close of trade.

The Silicon Valley group joins Apple, which first reached USD1 trillion (Sh100tr) in 2018 and on Thursday showed a valuation of some USD1.38 trillion (Sh139tr); and Microsoft, now valued at some USD1.26 trillion (Sh127tr).

Another tech titan, Amazon, rose above the trillion-dollar mark in September 2018 but has since declined to a value of around $930 billion (Sh93.8 trillion).

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.