Shares in Lumena Resources Corp dropped as much as 15.6 per cent yesterday after the industrial chemical maker revealed its controlling shareholder had pledged 20 per cent of the company's shares to obtain a personal loan. Suolang Duoji, who owns 37.5 per cent of Lumena, the world's second-largest maker of the industrial chemical thenardite, has pledged 400 million shares or a 20.5 per cent stake to BOC International for the loan. The move raised ratings agency concerns about Lumena's bonds and the stock closed 12 per cent lower at HK$2.42. 'Moody's had previously expressed concerns over Lumena's untested financial discipline and corporate governance due to its short track record as a listed entity,' said Moody's Investors Service senior credit officer Elizabeth Allen. 'This recent transaction raises Moody's concerns over these issues.' Although the pledge of shares did not appear to have had an impact on the company's operations or financial position, she said it added uncertainty over the stability of Lumena's financial profile. If loan repayments or terms are not met, it could trigger a change of control in the company, according to terms of Lumena's bonds. In October last year the company issued US$250 million in notes that will mature in 2014, carrying an interest rate of 12 per cent. The terms of the notes specified that if the stake of the controlling shareholder, Duoji, fell below 30 per cent, it would trigger a change of control. In such a case, the company would be obliged to offer to buy all outstanding notes at 101 per cent of the principal amount, plus interest. 'It is uncertain as to whether the company would have the ability to do so,' Moody's said. The ratings agency said it had put Lumena's corporate and bond ratings on review for possible downgrade from B1.