Nexon Korea Corp. said Saturday that no data of MapleStory overseas members was leaked in the recent security breach that compromised private details of 13.2 million Korean online game players.

The massive private data leakage hit gamers of the internationally popular online game earlier this week, affecting nearly three quarters of the 18 million MapleStory users in South Korea.

"We operate separate servers in each country," said a Nexon spokesman. "Only Korean users' information was affected."

Nexon discovered on Thursday that millions of user IDs, players' names, passwords and residential registration numbers on MapleStory was leaked from its servers to unidentified hackers.

Passwords and residential registration numbers, an equivalent of social security numbers in the United States, were encrypted, but affected users were still advised to change their passcodes on other Web sites, the company added. 

Nexon reported the case to the Korea Communications Commission, the telecommunications regulator, the following day and requested a police investigation.

The security breach comes weeks before the planned initial public offering of the unlisted company's Japan affiliate. Media reports said Nexon aims to raise $1.3 billion in its initial public offering in Tokyo scheduled on Dec. 6.

Nexon, which made KartRider and MapleStory, two globally endeared games, especially among teenagers, is one of the two leading online game developers in South Korea, along with NCsoft Corp.

The recent hacking is the second largest online security breach in the country's history. In August, private details of 35 million subscribers of the Nate search engine and Cyworld social networking Web site were leaked. (Yonhap News)