Korea Telecom revealed its Q4 net profit grew 12.5% to 210.6 billion won ($187.6 billion), as asset sales compensated for a decline in operating income.
The company reported a 16.7% decrease in operating income to 287.6 billion won, and revealed its revenue from wireless and fixed telephony services both declined.
Wireless revenue fell 2.4% year-on-year to 1.71 trillion won. Voice revenue was particularly hard-hit, falling 24.5% as a result of KT's 1,000 won reduction in its base rates made in August at the behest of regulators.
Revenue from fixed telephony services fell 10.5% to 929.9 billion won over the same period. KT last year decided to halt further investment in its fixed telephony services.
Internet revenue grew 2.3% to 663.6 billion won, with the company's broadband subscriber base growing to 7.8 million, although broadband revenue fell 3.9% to 453.9 billion won.
But KT's overall operating revenue grew 24.7% to 6.37 trillion won, thanks to the inclusion of revenue from new subsidiaries including BC Card.
BC Card is South Korea's largest credit card processing company. Around this time last year, KT became the top shareholder of the company to support its mobile payment ambitions.
KT's results were published days after rival SK Telecom revealed its own Q4 profit fell 61% to 196 billion won, pushing its FY11 profit down 10.4%.