(AP)—Baidu Inc., which operates China's most popular search engine, said Friday its quarterly profit rose 34 percent over a year earlier as its mobile business grew.

The Beijing-based company said it earned 3.5 billion yuan ($571.1 million) in the three months ended June 30. Revenue rose 58.5 percent to 11.9 billion yuan ($1.9 billion).

Baidu and other Internet companies are building mobile e-commerce and other services as Chinese users shift rapidly to going online using smartphones and . Baidu dominates traditional Internet search but is a much smaller presence in mobile.

The contribution of mobile to Baidu's total revenue rose above 30 percent for the first time, chairman Robin Li said in a statement.

"We had a great quarter as we continued to build very strong mobile momentum," Li said.

The mobile effort was reflected in a doubling of selling and administrative expenses to 2.1 billion yuan ($346.4 million), which the company said was due to higher promotional spending.

For the current quarter, Baidu forecast a 50.9 to 55 percent rise in revenue over a year earlier to 13.4 billion to 13.8 billion yuan ($2.1 billion to $2.2 billion).