Last week, South Korean tech firms Netmarble and Kakao and private equity fund MBK Partners submitted letters of intent to buy the holding firm, NXC Corp, in what could be one of South Korea's biggest deals, a source familiar with the matter said.

In separate emailed responses, Amazon and EA said they "don’t comment on rumours and speculation." Comcast did not immediately respond to emailed requests for comments.

A Nexon spokeswoman declined to comment.

(Reporting by Hyunjoo Jin and Heekyong Yang; Editing by Muralikumar Anantharaman)