The decision comes after the national government extended the current alert level 2.5 - the second-highest on Korea’s five-tier system - until 31 January.
The three casinos - Busan Lotte, Millennium Hilton Seoul and Gangnam COEX - had been set to reopen on 18 January, but that date has been pushed back, despite daily coronavirus case numbers in the country falling by more than half.
In Seoul, Millennium Hilton Seoul and Gangnam COEX have been closed since 24 November, while the Busan property closed on 1 December.
Fellow foreigner-only casino operatory Paradise Co continues to operate in Busan, Seoul and Incheon, having briefly paused operations at Paradise Walkerhill in Seoul in December.
All casinos in Seoul were previously forced into a temporary shutdown on 24 November, with GKL stating that it expected to lose KRW5.1bn ($4.6m) in net sales because of the closures.
The latest closures meanwhile look set to cause further losses, with GKL expecting to record a KRW27.5bn loss in casino sales, based on average daily net sales from July to September 2020.
