The Ontario Teachers’ Pension Plan earned a 13.0% rate of return in 2012 as its net assets grew to $129.5 billion compared with $117.1 billion at the end of 2011.

The plan said the results beat its benchmark of 11% by two percentage points.

Investment earnings for 2012 were $14.7 billion, versus $11.7 billion in 2011.

“Returns earned above our benchmark directly support the goal of pension security and demonstrate the value of our approach to active investing,” chief executive Jim Leech said.

“The investment team successfully navigated significant risks and turmoil in the global economy again in 2012 to earn an excellent rate of return.”

Leech, 65, confirmed Tuesday he has advised the board that he plans to retire by the end of 2012. He has been the pension fund manager’s CEO since 2007. He joined Teachers in 2001 to manage its private equity portfolio.

Teachers’ equity investments returned 14.2% for the year to bring the total public and private investments in the asset class to about $59.5 billion at the end of last year compared with $51.7 billion at the end of 2011.

Teachers’ Private Capital investments totalled $12.0 billion at the end of 2012 compared with $12.2 billion a year earlier and earned 18.6%.

Fixed income assets totalled $60.0 billion at year end compared with $55.8 billion at the end of 2011 and returned 5.1%, while commodity investments lost 1.9% but the amount invested grew to $7.0 billion at the end of the year from $5.7 billion at the end of 2011.

Real assets, which included real estate, infrastructure and timberland, totalled $28.7 billion compared with $25.8 billion and earned 14.7%.