SK hynix Inc., the world's No. 2 memory chip maker, said Thursday its net profit surged 348.9 percent in the first quarter from a year earlier on the back of improved sales in dynamic random access memory (DRAM) chips. Net profit came to 802.2 billion won (US$771.7 million) in the January-March period, soaring from 178.7 billion won in the previous year, the company said in a regulatory filing.