China Metallurgical Group plans to seek dual listings in Hong Kong and Shanghai as early as September to raise up to $4 billion, said sources with direct knowledge of the deal, which could be the world's second-largest fundraising this year.

The company was still awaiting approval from the authorities, but hoped to kick off an international road show in early September, two sources told Reuters.

China Metallurgical aimed to issue A shares in China by mid-September and hoped to launch an H-share offering in Hong Kong before the end of the same month, they said.

The company has an iron mining joint venture in Australia with CITIC Pacific. Its businesses also include natural resources, scientific research and industrial engineering.

Morgan Stanley, CITIC Securities, CICC and Citigroup were handling the deal, they said.

Recent successful trading debuts in China and Hong Kong have fanned investor interest in chasing newly-listed stocks or initial public offering shares.

China State Construction Engineering Corp surged as much as 90 percent on its trading debut in Shanghai last week after its $7.3 billion IPO, the world largest this year, received an overwhelming response.

Hong Kong-listed BBMG, a Beijing-based building materials producer, soared 56 percent on the same day during its own debut.

China Metallurgical's IPO could be the second-largest fundraising in the world this year, surpassing a $3.6 billion IPO launched by Visa Inc's Brazilian affiliate VisaNet in June.

More companies are seen queuing up to tap the equities markets in Hong Kong and China.

Yingde Gases, a Chinese industrial gas company has applied to launch an IPO in Hong Kong to raise $300 million by the end of the year, banking sources told Reuters earlier on Thursday.

(Writing by Alison Leung and Moxy Ying; Editing by Chris Lewis)