Google's second-quarter profit rose 35 percent from a year ago to 1.25 billion dollars, led by strong growth outside the US market in online advertising operations, the Internet giant said Thursday.

The results however were below most Wall Street forecasts with a profit excluding special items of 4.63 dollars per share, compared with a consensus expectation of 4.84 dollars.

Google reported revenues of 5.37 billion for the quarter to June 30, an increase of 39 percent from a year earlier and up three percent from the first quarter.

Excluding traffic acquisition costs, the money Google pays to its partners, revenues totaled 3.9 billion dollars, a bit higher than most forecasts.

"Strong international growth as well as sustained traffic increases on Google's web properties propelled us to another strong quarter, despite a more challenging economic environment," said Eric Schmidt, Google's chief executive.

"As we continue to focus on innovating in our core business of search, ads and apps, we also look forward to enhancing the experience of our users and expanding the reach of our advertisers and partners with new technologies and formats, particularly as our integration of DoubleClick gains momentum and creates new opportunities in display advertising and elsewhere."

Google earlier this year completed its takeover of online advertising firm DoubleClick, strengthening its domination of the lucrative online ad business.

The leader in Internet search said its own sites generated revenues of 3.53 billion dollars, or two-thirds of the second-quarter total.

Google's partner sites generated revenues, through its AdSense program, of 1.66 billion dollars, or 31 percent of the total.

Revenues from outside of the United States accounted for 52 percent of Google's total and provided a modest lift to the company because of the weak dollar.

The company said it expects "to continue to make significant capital expenditures" but offered no details in its earnings report.

Google's planned tie-up with Yahoo for online advertising has drawn scrutiny from Washington and complaints from rivals that it would dominate the Internet advertising business.