In a blog post, the head of the Japanese technology giant sought to reassure customers, saying the company is focused on investigating and fixing the hacker attack.

Sony Corp. Chief Executive Howard Stringer has apologized for “inconvenience and concern” caused by the big security breach that compromised personal data from more than 100 million online gaming accounts.

In a blog post, the head of the Japanese technology giant sought to reassure customers, saying the company is focused on investigating and fixing the hacker attack.

“We are absolutely dedicated to restoring full and safe service as soon as possible and rewarding you for your patience,” Mr. Stringer wrote in his first public comments since Sony shut down its PlayStation Network on April 20.