Google parent Alphabet Inc reported a 24 per cent jump in quarterly revenue on robust mobile advertising.

The company's shares were up nearly 3 per cent at US$1,020 after the bell on Thursday. They have gained 25 per cent this year.

On a consolidated basis, the company's revenue rose to US$27.77 billion in the third quarter ended Sept. 30.

Ad revenue surged 21.4 per cent to US$24.07 billion.

Google is expected to generate about  US$72.42 billion in net digital ad revenue worldwide this year, a 15.7 per cent jump from a year earlier, according to research firm eMarketer.

Paid clicks, where an advertiser pays only if a user clicks on ads, rose 47 per cent. Analysts on average had expected an increase of 46.1 per cent, according to data and analytics firm FactSet.

Alphabet's total traffic acquisition costs, a measure of how much money the company spends to attract users to its search engine, rose 31.6 per cent.

Losses from Alphabet's "Other Bets" - separate business units including the Waymo self-driving car unit, Google Fiber, thermostat-maker Nest, and life sciences firm Verily V - narrowed to US$812 million from US$861 million.

The company's net income rose to US$6.73 billion, or US$9.57 per Class A and B share and Class C capital stock, in the third quarter ended Sept. 30 from US$5.06 billion, or US$7.25 per share, a year earlier.