(Corrects to show Lazaridis now controls, rather than holds direct ownership of, 8 percent of the company's shares in paragraph 2)
TORONTO, Oct 10 (Reuters) - BlackBerry Ltd co-founder Mike Lazaridis has increased his stake in the struggling smartphone maker and is considering buying the entire company, according to a securities filing on Thursday.
Lazaridis, who now controls 8 percent of the company, has engaged Goldman Sachs and Centerview Partners LLC to assist with a strategic review of his stake. He held almost 5.7 percent as of the end of 2012, according to Thomson Reuters data. (Reporting by Alastair Sharp; Editing by Gerald E. McCormick)