SEOUL -(Dow Jones)- South Korea's SK Telecom Co. (SKM, 017670.SE) on Sunday said it will start offering Apple Inc.'s (AAPL) iPhone 4 starting March 16 in a move to broaden its product lineup and to address growing demand for smartphones. "SK Telecom is proud to offer iPhone 4 on the nation's top network," So Jin-Woo, president for SK Telecom's platform business, was quoted as saying in the emailed statement. "Our customers will benefit from flexible tariff plans tailored to their unique usage needs along with a high level of customer care." Customers may preregister for iPhone 4 beginning March 9 at SK Telecom's official online store, T Smart Shop (www.tsmartshop.co.kr), or at one of 1,500 authorized SK Telecom T World retail stores, according to the statement. Last month, SK Telecom, the country's largest mobile carrier by revenues, said it will start offering iPhone 4, signaling the end of the exclusive distribution of the touchscreen device by rival mobile operator KT Corp. (030200.SE) The move comes as South Korean mobile carriers are making a big push into the wireless data services market in order to make up for declining revenue from voice calls as the local telecom market has become highly saturated. Greater usage of smartphone devices like the iPhone would boost their efforts.