Samsung said: "Shipments of the Galaxy Note 7 are being temporarily delayed for additional quality assurance inspections."
There are reports in South Korea and the US of the Galaxy Note 7 "exploding" either during or just after charging.
However, it is unclear whether the delay is because of these reports.
Pictures and videos shared online depict charred and burnt handsets.
Shares fell as much as 3.5% during trade in Seoul before making a partial recovery to close 2% down on the day.