UPDATE 1-Sina Q4 tepid, sees weak Q1 revenue

* Q4 EPS $0.46 vs est $0.45

* Sees Q1 rev $93-$96 mln vs est $95.2 mln

* Shares down 4 pct after hours (Adds results, outlook, share movement)

March 1 (Reuters) - Sina Corp , China's largest Internet portal, reported a quarterly profit that edged past expectations lifted by its hot microblogging product but forecast first-quarter revenue largely below estimates.

The company reported posted a fourth-quarter net loss of $100 million, or $1.51 a share. Mobile-related revenue dropped 26 percent to about $21 million.

Online advertising revenue soared 30 percent to $82.5 million in the quarter as user traffic soared on interest in Sina's Twitter-like product Weibo.

Revenue, excluding Sina's carved-out real estate advertising business, rose 12 percent to $105 million, in line with analysts' expectations of $104.6 million, according to Thomson Reuters I/B/E/S.

At the end of the quarter, Sina had more than 100 million subscribers for Weibo, double that of four months ago. The firm has said Weibo will start generating revenue in the first half of 2011 via the sale of virtual items and advertising space.

Sina competes with Tencent Holdings and Sohu.com Inc in China's near-$600 million portal advertising market, in which it has pole position.

It expects first-quarter adjusted revenue of $93-$96 million. Analysts were expecting revenue of $95.2 million.

Sina's shares were down 4 percent at $79.10 in trading after the bell. They closed at $82 on Tuesday on Nasdaq.

The stock has risen 15 percent this year on buzz surrounding the money-making prowess of Weibo, and 44 percent since the company reported third-quarter results on Nov 11. (Reporting by Sayantani Ghosh in Bangalore and Melanie Lee in Shanghai; Editing by Saumyadeb Chakrabarty)