China's largest search engine Baidu said its profit in the fourth quarter of last year surged 77 percent year on year to 2.05 billion yuan ($326.3 million) as advertisers increased spending on online marketing.

Baidu, which controls a 73-percent share of China's search engine market, reported revenue of 4.47 billion yuan ($709.5 million) in the fourth quarter, surging 83 percent.

In a conference call with investors, Baidu's CEO Robin Li said profits were driven by a growing number of customers and their willingness to allocate more funds to online advertising.

Baidu's active online marketing customers rose 12.7 percent over a year earlier to 311,000. Revenue per customer rose 61.8 percent to 14,400 yuan ($2,288).

Li said the company would continue to explore long-term international opportunities and was seeking to begin monetizing mobile search traffic.

"Mobile will represent an ever larger percentage of our local traffic, and starting from this year, we make greater efforts to better serve our customers on the mobile platform," he said.