HONG KONG (Reuters) - Shares in China's Qingdao Port International are set to open flat in their Hong Kong trading debut on Friday amid concern that the company could be hurt by a probe into metal financing at the world's seventh busiest port.

Global trading houses and banks on Thursday were scrambling to check on their exposure to the probe, as concerns grow that a crackdown into commodity financing could hit trade in the world's top metal buyer.

Trading sources have said port authorities are conducting the investigation but it is not clear which authorities are in charge. Port officials have declined to comment except to say that operations are running as normal.

Qingdao Port International is the primary operator of the port, handling about 76 per cent of the port's total cargo last year.

The shares are indicated to open at HK$3.76, the same as its IPO price. The benchmark Hang Seng index was indicated to open up 0.5 per cent.

The rare fixed-priced initial public offering raised US$377 million, with the company selling 705.8 million new shares, while shareholder Qingdao Port (Group) offered 70.58 million existing shares. The funds will be used to expand facilities at the port.