Jan 23 (Reuters) - Chinese copper producer Zhongtiaoshan Non-ferrous Metals Group is close to securing a backdoor listing for smelting unit Northern Copper after Shenzhen-traded Nafine Chemical Industry Co announced details of a planned restructuring.

The listing will allow Northern Copper, which is upgrading and expanding its Houma smelter in China's Shanxi province, to be publicly traded on the Shenzhen Stock Exchange under Nafine's stock code and raise financing, without the need for an initial public offering.

The complex deal, which is backed by the Shanxi government, will see Nafinea salts and chemicals producer under Shanxi Coking Coal Group, acquire all of Northern Copper for 4.4 billion yuan ($679 million) in cash and shares, Nafine said in a filing to the Shenzhen Stock Exchange late on Friday.

Zhongtiaoshan, a member of the group of 14 state-backed Chinese copper producers known as the China Smelters Purchase Team (CSPT), will receive most of these shares and become the controlling shareholder of Nafine with a 49.07% stake, Nafine said in the filing.

The restructured company will be ultimately controlled by the Shanxi government, Nafine said, adding that the deal needed the approval of China's securities regulator.

Northern Copper, which counted South Korea's SK Networks as a 45% shareholder from 2008-2014, will make good use of the listing as a fundraising platform, Zhongtiaoshan said in a statement on Dec. 31.

The revamp of the Houma smelter, which was shut in 2018, is intended to raise Zhongtiaoshan's overall copper smelting capacity to 500,000 tonnes a year. ($1 = 6.4810 Chinese yuan) (Reporting by Tom Daly Editing by Robert Birsel)