China's most popular online video website Youku narrowed its loss in the second quarter as advertising revenue jumped.

The company's net loss shrank 55 percent from the same period last year to US$4.4 million in the three months ended June 30, the Beijing-based website said yesterday.

Sales surged 178 percent to US$30.6 million as advertisers tried to entice Youku's users to buy their products.

Youku said it spent US$7.7 million in the second quarter to expand its licensed video content.

Chairman and Chief Executive Officer Victor Koo said the company will enhance wireless products and services for smartphone users.

Advertising income on domestic video websites nearly doubled to 1 billion yuan (US$155 million) in the second quarter from a year go.

Youku raised US$233 million after selling its shares at US$12.8 apiece on the New York Stock Exchange in December.