(Telecompaper) South Korean operator SK Telecom posted first-quarter revenues of KRW 4.45 trillion, which represents an increase of 2.7 percent, mainly boosted by 5G subscriber base growth and development of new businesses, including media, security and commerce. Operating income was down 6.4 percent to KRW 302.0 billion due to expanded 5G network investment costs including 5G spectrum licensing fees. First-quarter net income amounted to KRW 306.8 billion, plunging 17.9 percent affected by factors including decreased equity method gains from SK Hynix.