Alphabet, the parent firm for Google, became the world's most valuable company today as a jump in its share price helped it vault past tech rival Apple.
In opening trade on Wall Street after a robust earnings report, Alphabet shares rose 2.9% to lift its market capitalisation to $543 billion.
Apple's value declined to $530 billion with a modest dip in trading.
Alphabet's quarterly profit rose 5% to $4.92 billion on the back of strong online advertising revenue, particularly from searches done by Christmas shoppers using smartphones or tablets.
Google's ad revenue climbed globally, gaining on both mobile devices and desktop computers, according to Alphabet chief financial officer Ruth Porat.
The California-based Internet giant said its revenue topped $21.3 billion in the final three months of last year.
The earnings report was the first in which recently formed parent corporation Alphabet separated money made by Google from what it calls "Other Bets" such as its work on self-driving cars or providing Internet service using high-altitude balloons.
The new structure under Alphabet is expected to offer more transparency for investors worried about Google investing in money-losing projects.
While Google is best known as the dominant player in Internet search, it has launched a variety of trail-blazing projects in recent years that are marginally related at best to its core operation.
Alphabet subsidiaries include Google, Nest Labs, and Google X labs devoted to new technologies such as self-driving cars, along with such projects as smart "Google Glass" spectacles, drones, health care and Google TV - none of which has become a major source of income.
Industry tracker eMarketer expected Google to remain the dominant player in worldwide search advertising, raking in $45.58 billion in revenue this year to claim a share just shy of 57% of total spending on such ads.
