Naver Corp., South Korea's top Internet portal operator, on Thursday released weaker than expected fourth-quarter earnings, sending its stock price to a one-week low.

Net income came to 134.5 billion won (US$124.2 million) in the October-December period, more than doubling from 54.1 billion won a year earlier, the company said in a regulatory filing.

But the fourth-quarter reading was well below the median estimate of 163.2 billion won suggested by South Korea's nine brokerage houses, according to the data compiled by Yonhap Infomax, the financial news arm of Yonhap News Agency.

Shares of Naver traded 5.28 percent lower at 736,000 won on the main bourse Thursday versus benchmark KOSPI's 0.54 percent decline.

The fourth-quarter results were released before the stock market opened.

Naver said its operating profit reached 196.1 billion won for the fourth quarter of last year, up 30.3 percent from a year earlier, with revenue also increasing 19.3 percent to 750.2 billion won over the cited period.

"The fourth-quarter operating profit consensus was roughly at 220 billion won," said Joseph Chung, an analyst at NH investment & Securities Co., casting a gloomy outlook over the share price of Naver.

For all of 2014, Naver posted 456.6 billion won in net profit, down 75.9 percent from a year earlier. However, its annual operating profit rose 50.1 percent on-year to 760.4 billion won last year, with sales rising 22.3 percent to 2.76 trillion won.

Naver said the LINE business lent support to its overall growth last year, as the messaging app unit saw its fourth-quarter revenue advance 62 percent on-year to reach 221.7 billion won.

Although the South Korean market is dominated by its rival Kakao Talk serviced by Daum Kakao Corp., LINE emerged as one of the most popular mobile messengers in Asian markets, boasting around 560 million subscribers worldwide.

The number of monthly active users, meanwhile, came to 181 million at end-2014, up 37 percent from the 132 million posted a year earlier.

Naver said its messaging service continued to expand footing, especially in Japan, Taiwan, Thailand and Indonesia in the fourth quarter, on the back of the increase in the penetration rate of smartphones and fast-changing business environments.

Of its fourth-quarter revenue, Naver generated 67 percent of the profit from the South Korean market and the other 246 billion won from overseas.

The revenue from advertisements came to 540.5 billion won during the October-December period, up 13.7 percent from a year earlier on the back of the strong gains from mobile platforms. The overseas market accounted for 12 percent of such revenues.

On the other hand, foreign markets accounted for 90 percent of its contents business revenue, which came to 199.1 billion won.

"Naver has continued to expand the portion of overseas markets and maintained the growth in overall revenue," said Kim Sang-hun, who heads the company. "This year we will launch new services that will add to the convenience of users and keep the robust growth trend going."

Naver added it is also planning to expand its mobile payment platform business this year. The service, dubbed LINE Pay, was launched in Japan in December, but is yet to operate in other countries, including South Korea.

 "We have not yet decided whether to jump into the financial industry in a full-fledged manner," Kim added, apparently referring to the South Korean government's deregulation drive that aims to encourage investment in Internet-only banks to be introduced in the first half of 2015.

The company said that it will pay out dividends worth 782 won per share for a combined amount of 23 billion won. (Yonhap)