SEOUL, May 10 (Reuters) - South Korea's Naver said on Friday it is exploring various options including the potential sale of its stake in the company that controls LY Corp which operates the popular messaging app Line.

In a statement, Naver, which holds an equal stake with SoftBank in a joint venture that controls LY Corp, apologised for the recent security breach that led the Japanese government to issue an administrative guidance.

"Naver will continue to put top priority on Naver shareholders and on raising the corporate value of Naver and LINE Yahoo as its major shareholder and partner as we make important decisions," it said in a statement.

"Related to the issue at hand, we are negotiating with SoftBank in good faith and open to all possibilities including the sale of our stake to achieve the best outcome for the company," it said.

LY Corp admitted in November last year that there had been unauthorised access of its systems by a third party via Naver's cloud system. This led to the leak of the personal data records of more than 300,000 Line users and others.

Although the guidance from Japan's internal affairs and communications ministry about the data leak did not explicitly mention a sell-down, it did direct LY Corp to "review the relationship where the outsourced company has a significant degree of capital control", referring to Naver.

Since the move by the Japanese government, Naver and the South Korean government have faced domestic criticism for not taking a more proactive stance to protect Naver's interest in LY Corp.

LY Corp said on its website that more than 95 million monthly active users used Line in Japan as of March last year, and it had another 83 million users in Thailand, Taiwan, and Indonesia. Line was launched in 2011. (Reporting by Jack Kim Editing by Ed Davies)