South Korean telecom regulator KCC has ordered the nation's mobile operators to reduce service charges by November.
The KCC has told carriers to lower charges including subscription fees, wireless-data rates and bundled-product costs, media reports said.
But the move could hurt South Korea's three mobile operators, which are already struggling with slim profit margins, largely because of their high marketing cost.
The move follows an election promise by president Lee Myung-bak to reduce mobile tariffs by 20%, following an OECD report which said prices were among the highest in the world.
SK Telecom has agreed to cut its subscription fees 27%, its wireless data rate 19% and replace its ten-second pulse system with one-second billing. KT will cut its subscription charges 20% and its wireless data rate by up to 62%, while LG telecom will reduce its voice rates by up to 25%.