Sina Corp, China's largest Internet portal, said net profit fell 60 percent as the firm spent heavily on investment in its highly popular microblogging service, Weibo.

The earnings were slightly above Wall Street expectations and Sina's shares were up nearly 7 percent in after-hours trading at $99.

Sina, which rolled out its Weibi virtual currency this month, is trying to generate revenue from Weibo and turn it into a full-fledged social networking site, pitting it against the likes of Kaixin001 and Renren Inc.

Sina said on Wednesday it earned a second-quarter net income of $10 million, or 15 cents a share, compared with $25.2 million or 38 cents a share for the same period a year ago.

Excluding one-off items, it earned 20 cents a share, beating the average forecast of earnings of 19 cents a share, according to Thomson Reuters I/B/E/S.

Revenue excluding Sina's separate real estate advertising business rose 21 percent to $114.3 million, within the range of its forecast of $112 million to $115 million.

For the third quarter, Sina expects adjusted revenue between $123 million and $126 million, versus analysts' expectations of $125.7 million.

Advertising revenue jumped 26 percent year-over-year to $91.8 million in the second quarter, while mobile-related revenue declined 2 percent to $19.5 million.

(Reporting by Alexei Oreskovic in San Francisco and Melanie Lee; Editing by Phil Berlowitz and Matthew Lewis)

China