Naver Corp., South Korea's top Internet portal operator, said Thursday its third-quarter net profit almost doubled from a year earlier as overseas sales, aided by its mobile messenger service LINE, sharply increased.

Net profit reached 143 billion won (US$136 million) in the July-September period, compared with 74.4 billion won a year earlier, the company said in a regulatory filing.

Operating income came to 189 billion won during the third quarter, rising from 101 billion won the previous year.

Sales reached 700 billion won in the same period, up 22.3 percent from a year earlier, it said.

Overseas sales reached 231 billion won in the third quarter, rising 52 percent from a year earlier to account for 33 percent of its total revenue.

Domestic sales, however, declined 2.5 percent on-year to 469 billion won over the cited period, it said.

Sales from its free messenger app LINE totaled 209 billion won, up 57 percent from a year earlier.

LINE, launched in June 2011, provides services in 17 different languages, attracting users not only from South Korea and Japan but also from the United States, Mexico and Malaysia.

The service had 560 million global users as of Oct. 9, with 54 million of them in Japan. Thailand, Taiwan and Spain accounted for

33 million, 17 million and 18 million users, respectively. The app has an estimated 10 million users in South Korea, where its main rival, Kakao Talk, dominates the market with 35 million users.

"The LINE chat app holds a dominant position in Japan, Taiwan and Thailand," said Hwang In-joon, Naver's CFO during a conference call. "We are also seeing a rise in subscribers in Mexico, Colombia and in the Middle East."

But Naver did not reveal key data, including the number of its subscribers, monthly active users (MAUs), the key gauge for chat app operators, and average revenue per user. 

Industry sources estimate LINE's MAU at 170 million.

Its advertisement sales rose 16.5 percent on-year to 498 billion won, and sales from contents jumped 62.8 percent to 191 billion won.

Shares of Naver closed at 750,000 won on the Seoul bourse, down

3.6 percent from the previous session's close, as its third-quarter operating income fell short of a market consensus of 201 billion won.

The third-quarter earnings were released before the market opened. 

In September, Naver said it would not list its Japan-based affiliate LINE Corp., which operates the messaging service, in the U.S. and Japanese stock markets this year, bucking market speculation that the messenger platform would go public by end-year as the service is gaining popularity among smartphone users around the world.

Naver said Wednesday that it plans to buy back 265 billion won worth of its shares in a bid to boost its stock price.

"The share buyback is part of our efforts for shareholder rewards," said Hwang. "At the moment, we don't have any plans to cancel stocks bought." (Yonhap)