Giant Chinese courier company SF Holdings (Group) has struck a 43.3 billion yuan ($6.6 billion) deal with a little-known metals company that effectively gives the firm known as 'China's Fedex' a backdoor route to a listing on the Shenzhen stock market.

With an eye on attracting investors as it lines up expansion overseas, SF Holdings has reached an asset swap and new share accord with Maanshan Dingtai Rare Earth & New Materials Ltd, the latter said in a filing.

Under terms of the deal, which is subject to regulatory approvals, Dingtai will officially acquire SF, funding the purchase by issuing new shares to the courier. Reinvented as a logistics company, Dingtai will then be controlled by SF, whose founder and Chairman Wang Wei will run the new business.

SF's 'backdoor listing' is the latest in a series of moves by big, privately held Chinese firms seeking a quicker route to a stock market presence than a time-consuming traditional initial public offering. The plan by SF is the biggest such deal since digital advertising company Focus Media's $7.2 billion backdoor listing last year.

The planned deal comes weeks after Chinese regulators unveiled plans to tighten scrutiny of companies seeking backdoor listings to benefit from top valuations in mainland China.

Trading in Dingtai shares, suspended since April 5, will remain halted pending further notice. Dingtai last traded at a price-to-earnings ratio of 126 times, Thomson Reuters data showed, giving it a market value of about $500 million.

SF, the main competitor in China for international courier firms like DHL and Fedex Corp, didn't respond to requests for comment. With logistics a key development focus area for China in the coming years, its listing follows similar moves by smaller peers YTO Express and STO Express.

Targeting a 60 percent jump in net profit to 3.48 billion yuan in 2018 from this year, SF had previously filed for clearance to launch an IPO, Thomson Reuters publication IFR reported.

In an interview last year, an executive told Reuters SF, which already delivers to more than a dozen countries including the United States and Japan, was planning major expansion into Southeast Asia and Europe that would see a rapid build-up in its fleet of aircraft.

Under terms of the deal, Dingtai also plans to sell new shares to 10 private investors, raising 8 billion yuan to upgrade logistics facilities.

CITIC Securities, Huatai United Securities and China Merchants Securities acted as financial advisers for the deal.