China Molybdenum Co Ltd, the country's largest manufacturer of the soft metal widely used in industry, has revealed plans to raise as much as 18 billion yuan ($2.8 billion) via a share placement.

CMOC shares rose 5.3 percent to close at HK$1.59 (20 cents) on Monday, following the share placement announcement, as the benchmark Hang Seng Index dropped 0.22 percent.

Trading in its Shanghai shares was suspended pending an announcement.

The Chinese mining-and-processing company, which earlier this month agreed to buy an African copper operation from Arizona-based mining company Freeport-McMoRan Inc for $2.65 billion, plans to issue 5.68 billion new shares to investors at 3.17 yuan each, with proceeds to be used for what it called asset purchase projects.

The company has newly announced two overseas acquisitions worth a combined $4.15 billion by its wholly owned offshoot CMOC Limited.

It had previously said the purchases were to be funded with cash and undrawn credit facilities, based on CMOC's existing resources.

But that prompted Shanghai Stock Exchange to ask for details on the amount of debt involved, and what borrowing arrangements had been put in place with which banks.

The regulator also asked CMOC to conduct an analysis of the impact new debt might have, its asset-to-liability ratio, and the measures that CMOC would take to deal with any resulting financial issues.

Demand for molybdenum has been declining both home and abroad, and as a result Chinese manufacturers are under considerable pressure, resulting in falling profit and dropping investment.

CMOC floated in Hong Kong in 2007, and then listed on the Shanghai Stock Exchange in 2012.

It halted trading on April 28 at a price of 3.37 yuan per share in Shanghai, while continuing to trade in Hong Kong.

CMOC revealed on May 9 it had bought an operation which owns 56 percent interest in the Democratic Republic of Congo's Tenke Fungurume copper-cobalt mine.

Then on April 28, it announced CMOC had entered a share purchase agreement with Anglo American Plc, to acquire the latter's niobium and phosphate business in Brazil for $1.5 billion.

CMOC previously bought a controlling 80 percent stake in copper deposit Northparkes Mines from Rio Tinto for $820 million.

Tenke Fungurume produced 204,000 tons of copper and 16,000 tons of cobalt in 2015, with total sales revenue of $1.38 billion.

World demand for cobalt, particularly, is currently being driven by its use in mobile phones and, increasingly, electric car batteries.

CMOC Chairman Li Chaochun said he now expects the latter acquisition to be completed by the end of the year.

He said the purchase is consistent with the company's strategic objective to expand and diversify its international portfolio with high-quality assets located in prolific mining regions that will promise significant long-term growth.

Also due to be completed within the second half of the year, the Anglo American deal, meanwhile, will help enhance the company's pole position in alloy manufacturing in China, said Kalidas Madhavpeddi, CEO of CMOC International.