(Bloomberg) -- Another two HNA Group Co. units tumbled on Friday, becoming the debt-laden Chinese conglomerate’s latest subsidiaries to plunge this week after ending a months-long halt of their shares.

Flagship Hainan Airlines Holding Co. dropped by the 10 percent daily limit to 2.91 yuan, heading for its lowest close in more than three years, and CCOOP Group Co. fell as much as 10 percent during early trading on Friday in Shanghai and Shenzhen. Two of other HNA units -- Bohai Capital Holding Co. and HNA-Caissa Travel Group Co. -- extended declines after they resumed trading this week. Three HNA units remain halted.

The four companies -- one of which was suspended as far back as November -- have lost about $3 billion in market value since they resumed trading. The units cited major restructurings for the suspensions, though analysts have pointed out there may be other motives given that Chinese companies have a history of using trading halts to prevent their stocks from falling further.

The resumption came as Hainan Airlines plans to raise as much as 7 billion yuan ($1 billion) by selling shares to investors, including an arm of Singaporean state-investment company Temasek Holdings Pte, as part of a restructuring.

HNA’s other suspended shares are:

Fortunately for HNA, which pledged shares in all of its suspended units as collateral for borrowings, the risk of margin calls isn’t high even if the stocks continue to fall. China’s government recently restricted forced liquidations of pledged shares, according to people familiar with the matter.

(Updates third paragraph to say one unit was suspended as far back as November. An earlier version of this story was corrected to reflect that two units resumed trading.)

To contact the reporter on this story: Prudence Ho in Hong Kong at pho83@bloomberg.net

To contact the editors responsible for this story: Young-Sam Cho at ycho2@bloomberg.net, Sam Nagarajan

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