Regulators have banned SK Telecom Co Ltd, KT Corp and LG UPlus Corp from signing up new customers or replacing phones for some existing customers for various periods totalling 45 days between March 13 and May 19.
The bans coincide with the planned global launch of Galaxy S5 on April 11, and sparked concerns that the key model could get off to a slow start in its home market.
The model already lacks sweeping hardware improvements and faces intensifying competition from smaller competitors at home and abroad.
SK Telecom, South Korea's biggest mobile carrier, said it started to offer the Galaxy S5 at 866,800 Korean won on Thursday, cheaper than its predecessor.
(Also see: Samsung Galaxy S5 launch price roundup)
The carrier has just over a week before it is forced to suspend attracting new customers, or some existing ones, from April 5 to May 19.
Its smaller rivals KT and LG UPlus, which are already under sales restrictions, have also started selling the phone to customers not covered by bans.
(Also see: Who stole Samsung Galaxy S5's buzz?)
The global sales of Galaxy S4 were weaker than expected, pulling down Samsung's earnings in October-December when the world's top smartphone maker lost market share to Apple Inc's iPhone 5s (Pictures) in the United States and Japan.
© Thomson Reuters 2014
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