SAN FRANCISCO (AFP) - Google on Tuesday reported that its annual revenue topped US$50 billion (S$61.4 billion) for the first time last year, as the Internet titan reported rising profits.

"We ended 2012 with a strong quarter," said Google co-founder and chief executive Larry Page.

"We hit US$50 billion in revenues for the first time last year; not a bad achievement in just a decade and a half."

The fourth quarter profit was up 6.7 per cent from a year earlier at US$2.89 billion, and for the full year Google's earnings grew 10 per cent to US$10.74 billion.

Revenue in the quarter that ended Dec 31 was up 36 per cent from the same period a year earlier at US$14.4 billion.

For the year, revenues grew 32 per cent to US$50.2 billion, helped in part by the acquisition of Motorola Mobility.

Google shares jumped more than 3.5 per cent to US$730.03 in after-market trading that followed release of the earnings figures, which topped most Wall Street estimates.

Google dominates the US digital advertising market, which grew 14.9 per cent to US$10.58 billion in the final three months of last year, according to eMarketer.

The market tracker estimated that Google takes in more than 41 per cent of digital ad revenue in the United States and "holds more share than any other company" when it comes to online, display and mobile advertising.