* Shares soar on debut; broader index falls
* Mid-day surge up 38 pct triggers temporary suspension of trading
* Shares later fall back to 17 pct above IPO price
* Sinohydro $2.1 bln IPO is biggest in mainland so far in 2011 (Adds closing share price, industry background)
By Soo Ai Peng and Samuel Shen
SHANGHAI, Oct 18 (Reuters) – Shares of Chinese dam builder Sinohydro Group rose 17 percent on their Shanghai debut on Tuesday as investors piled in to profit from an attractive valuation, boding well for other big China fundraisings in the pipeline.
The builder of the Three Gorges Dam, the world’s largest hydropower project, raised $2.1 billion in the mainland’s biggest IPO this year, but priced its shares at a significant discount to peers in the face of volatile equity markets.