Daum Communications Corp., the operator of South Korea's second-most visited portal, said Friday its second-quarter profit sank 23 percent on declines in its display advertising.

Net profit came to 178 billion won (US$160 million) in the April-June period, compared with a profit of 230 billion won a year earlier, Daum said in a regulatory filing.

Revenue gained 15.2 percent on-year to 127 billion won in the second quarter, while operating profit dropped 22.5 percent to 243 billion won over the cited period.

Daum attributed the slump in net profit to less demand for display adverts.

Daum said growth in search ads and game services were offset by a slower than expected expansion in its display advertising.

The company said it plans to focus on nurturing its search advertising platform and mobile growth this year. Daum also said it plans to upgrade its mobile application as well as add new features to its messenger service.

Shares of Daum were trading at 89,100 won on the Seoul bourse as of 9:10 a.m., down 0.45 percent from the previous session's close. The second-quarter business results were released before the market opened. (Yonhap News)