CEO Howard Stringer apologized for security breaches that may have compromised the personal data from more than 100 million user accounts.

"Let me assure you that the resources of this company have been focused on investigating the entire nature and impact of the cyber-attack we've all experienced and on fixing it," Stringer wrote on the company's U.S. PlayStation blog. "We are absolutely dedicated to restoring full and safe service as soon as possible and rewarding you for your patience. We will settle for nothing less."

Sony warned earlier this week that hackers may have stolen personal information from about 24.6 million accounts at its Sony Online Entertainment division. A week earlier, Sony warned 77 million users that their private account details, such as passwords, names, birthdates, addresses and credit cards, may have been compromised after the PlayStation Network was infiltrated by an unknown hacker.

Stringer, in his blog post, said "there is no confirmed evidence that any credit card or personal information has been misused."

Sony and Stringer have been criticized for their slow response to the security breach. The CEO said the company needed time to determine what happened.

"I know some believe we should have notified our customers earlier than we did. It's a fair question," Stringer said. " As soon as we discovered the potential scope of the intrusion, we shut down the PlayStation Network and Qriocity services and hired some of the best technical experts in the field to determine what happened. I wish we could have gotten the answers we needed sooner, but forensic analysis is a complex, time-consuming process."

Sony began investigating unusual activity on the PlayStation network on April 19, but didn't notify consumers of the breach until a week later.

Sony didn't specify when service could be restored, but in a separate blog post said it has begun the "final stages of internal testing of the new system, an important step towards restoring PlayStation Network and Qriocity services."