* Local media reports say MBK Partners to sell 30.9 pct in Coway
* Stock exchange asks Coway to comment on media reports
* MBK’s Coway stake worth nearly double the purchase price (Updates with reaction from Coway, background)
SEOUL, Aug 10 (Reuters) – Shares of South Korean water purifier maker Coway Co Ltd tumbled more than 10 percent on Monday following local media reports that private equity fund MBK Partners plans to sell a controlling stake worth nearly $ 2 billion.
The South Korean stock exchange has asked Coway to comment on whether MBK plans to sell its stake by 0900 GMT. An MBK spokesman declined to comment, while a Coway spokeswoman said the firm was making checks.
Coway, which also operates in overseas markets such as China, Malaysia and the United States, rents products such as water purifiers, air purifiers and bidets to consumers.
It reported a record quarterly operating profit of 112 billion won for the April-June quarter.
Coway shares slid 11.5 percent in morning trade to 92,500 won per share, valuing MBK’s 30.9 percent holding at about 2.2 trillion won ($ 1.9 billion) – still nearly double what company agreed to pay in 2012.
($ 1 = 1,165.4000 won) (Reporting by Se Young Lee; Editing by Subhranshu Sahu and Edwina Gibbs)