In documents filed with U.S. regulators on Friday, the pension plan disclosed the purchase of 7.79 million shares of BlackBerry during the third quarter ended Sept. 30.
The latest purchase makes Teachers one of the Top 10 holders of BlackBerry shares, according to data compiled by Thomson Reuters.
In total, Teachers now holds 8.23 million shares in BlackBerry, worth about US$86.7 million as of Friday's closing stock price.
The Waterloo, Ont.,-based hardware and services company began a dramatic turnaround attempt a year ago when it hired John Chen as its chief executive officer.
Chen, a seasoned veteran of the technology industry, immediately began an effort to reshape BlackBerry as a leaner operation focused mainly on the business community. He aims to make the company break even by the end of next February.
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