(Adds first-quarter outlook, updates after-hours share move)
Feb 24 (Reuters) - Sina Corp's revenue soared 43 percent in the fourth quarter, as its Weibo messaging service more than doubled advertising sales despite strong competition from Tencent Holdings Ltd's WeChat.
Weibo, one of several Chinese Twitter-like services, increased ad revenue by 163 percent to $56 million in the final three months of 2013. Sina Weibo has hired investment banks for a $500 million U.S. IPO later this year, a source told Reuters on Monday.
Still, shares of the Chinese company dipped 1.4 percent after Sina's overall results barely beat Wall Street's expectations. Investors are accustomed to seeing the Chinese Internet company outpace its targets by wide margins.
Sina posted non-GAAP revenue of $192.3 million in the fourth quarter, barely surpassing an average forecast for $192.2 million, according to Thomson Reuters I/B/E/S.
It recorded a twofold increase in non-GAAP net income to $33 million or 47 cents per share, beating by just a penny the 46 cents that analysts expected.
And it forecast non-GAAP net revenue of between $162 million and $167 million this quarter, broadly in line with Wall Street's expectations of about $165.2 million.
Chinese mobile messaging apps like Tencent's WeChat, or Weixin, have become venues of choice for users who want to express views without fear of government retribution. Weibo, one of several Twitter-like short messaging services, plans a listing in the second quarter, said the source, who was not authorized to speak publicly on the matter.
"As we enter 2014, we will continue to focus on growing Weibo's user base and user engagement through product innovation, as well as seizing opportunities to enable us for long-term growth," Sina Chief Executive Officer Charles Chao said in Monday's results statement.
Its stock fell to $75.00 in after-hours trading on Monday, compared with a closing price of $76.08 on the Nasdaq. (Reporting by Edwin Chan in San Francisco; editing by Matthew Lewis)