Shares of China Cinda Asset Management Co Ltd soared more than one-quarter in their first trading day, after becoming Hong Kong's biggest IPO so far this year by raising $2.5 billion.

Beijing-based Cinda, the first of the nation's four State-owned bad loan managers to go public, saw its shares close 25.69 percent higher at HK$4.50 (58 cents) on Thursday. The benchmark Hang Seng Index slid 0.51 percent to 23,218 points.

The shares opened at HK$4.30, 20 percent above the IPO price. Nomura Securities Co Ltd rated Cinda a "buy" and set a target price of HK$5.10.