July 20 (Bloomberg) -- Ontario Teachers' Pension Plan, Canada's third-biggest pension fund manager, sold about 11 percent of its stake in Canadian oil and natural-gas producer Nexen Inc., raising C$219.4 million ($210 million).

The Toronto-based fund manager said today in a regulatory filing it sold 6.5 million Nexen shares on July 18 at C$33.75 apiece. It now owns 53.7 million shares, or 10.2 percent of Calgary-based Nexen's outstanding stock.

The sale is part of a ``rebalancing'' of its portfolio, Teachers' spokeswoman Deborah Allan said. The fund manager leads a group that agreed last month to buy BCE Inc., Canada's largest phone company, for C$51.7 billion, including debt, in what would be the biggest private-equity buyout ever. The group will invest C$8 billion of its own money and borrow the rest.

At year-end, Nexen was Teachers' biggest stock holding, amounting to C$1.93 billion. Teachers', which manages C$106 billion in overall assets, only discloses its stock holdings once a year.

Shares of Nexen, whose operations range from the Middle East to the Alberta oil sands, have gained 11 percent this year. The stock fell 30 cents today to C$35.55 in Toronto Stock Exchange trading.

To contact the reporter on this story: Frederic Tomesco in Boston at tomesco@bloomberg.net.

Last Updated: July 20, 2007 16:36 EDT