Sina Weibo is displayed at Global Mobile Internet Conference 2011 in Beijing,April 27,2011.[Photo/CFP]

BEIJING - China's biggest Internet portal, Sina Corp, expects to monetize its most popular micro-blogging service, Sina Weibo, in the first half of next year, said a top official on Thursday.

The move reflects the enormous popularity of micro-blogging in China, and a number of service providers are trying to gain an upper hand in the market through different methods.

Charles Chao, chief executive officer of Sina, said the company is building advertising and payment systems for Weibo to prepare for future monetization.

"We are doing different experiments (on Weibo), but nothing large scale at all," said Chao during a conference call, adding that this year Weibo will not produce any revenue.

Micro-blogging has been fastest developing Internet service in the country this year. More than 40 percent of the country's Internet users - who totaled 485 million at the end of June - used the service, according to the latest report from the China Internet Network Information Center.

Betting on micro-blogging becoming the next big thing on the Internet, major players, such as Sina and Tencent Holdings Ltd, have been investing heavily in the service in terms of marketing and research and development.

Chao said Sina will continue this strategy to boost market share and the user base. Registered users of Sina Weibo had topped 200 million by the end of July, the company said. That's still lower than the 233 million that had registered with Tencent by the end of June.

However, at the same time, some players left the game. Baidu Inc, China's largest search engine, said earlier this month that it will completely shut down its micro-blogging service on Aug 22.

The service, which came online last September, required users to sign up with their real names and to prove their identities. This, combined with a lack of distinguishing features in the service, caused its closure, analysts said.

Sina's net income fell to $10 million in the second quarter, from $25.2 million a year earlier, it said in a statement, as a result of heavy spending on its micro-blogging service, despite higher online advertising sales.