Sony chairman and president Howard Stringer on Tuesday apologised to shareholders and customers over a massive data leak, which helped push its its share price to a two-year low this month. \"In April, we faced a serious challenge in the form of a cyber attack launched against the PlayStation Network, Qriocity and the network systems of Sony Online Entertainment,\" Stringer said at a meeting in Tokyo attended by about 5,900 shareholders. \"We are sorry for any concern and inconvenience that the incidents may have caused our shareholders, customers and stakeholders,\" he said. The company is expecting its third-straight annual loss this year. Stringer said Sony has worked to strengthen its information security systems, \"placing our highest priority on ensuring the security of our customers’ personal information, and regaining their trust.\" The Japanese electronics and entertainment giant has faced a series of cyber attacks and said more than 100 million accounts have been affected, making it one of the largest data breaches in the history of the Internet. Analysts say costs associated with the breach could be as much as $1 billion, but deeper damage to Sony\'s brand image could undermine efforts to link its gadgets to an online network of games, movies and music. Sony\'s PlayStation Network, its Qriocity music streaming service and Sony Online Entertainment were among other services targeted by hackers recently. The company has also suffered attacks on websites in Greece, Thailand and Indonesia and on the Canadian site of mobile phone company Sony Ericsson. In the year to March, Sony suffered a net loss of 259.6 billion yen ($3.2 billion), its third annual loss in a row, citing a large write-down in deferred tax assets in the wake of the March 11 earthquake and tsunami. But the company forecast a net profit of 80 billion yen for the year to March 2012. The Tokyo-based maker of PlayStation consoles and Bravia television sets was forced to shut plants in Japan after the quake and tsunami disaster hit supply chains, damaged some facilities and dampened consumer demand. Sony shares are around 28 percent below March 10 levels, before the disasters and data breaches took their toll, and hit a two-year low earlier this month.