The Fair Trade Commission(FTC) has ordered Samsung SDI to sell all of its remaining Samsung C&T shares in connection with a controversial merger between Samsung C&T and Cheil Industries. 

South Korea's trade watchdog issued the order on Monday in accordance with tightened regulations on cross-shareholding among affiliates of a conglomerate.

Under the measure, Samsung SDI is required to sell four-point-04 million Samsung C&T shares, worth 540 billion won, by August 26th. 

Samsung SDI secured around nine-point-04 million shares of Samsung C&T when it merged with Cheil Industries in 2015, but later had to sell five million of them by order from the FTC. 

The strengthened regulation on cross-shareholding practices was drafted late last year and was implemented on Monday.