In the midst of the economic slowdown, half the assets managed by the world's largest money managers are now pension fund assets, according to a new Towers Watson study.

Alternative assets managed on behalf of pension funds by the world's largest managers grew 16 percent in 2010 to $952 billion from $817 billion in 2009, according to research produced by consulting firm Towers Watson in conjunction with the Financial Times.

Total assets under management for these managers increased by 12 percent to $1.9 trillion. The Global Alternatives Survey covers five alternative asset classes: real estate; private equity fund of funds; fund of hedge funds; infrastructure and commodities and includes rankings of the top managers in each area.

Top 5 Ranking

Pos., Name of parent org., Main country of domicile, Pension AuM  (USD mn), Total AuM (USD mn)

1. Macquarie Group, Australia, 60,317.4, 92,152.2                    

2. Prudential Financial, U.S., 41,992.7, 44,767.3                           

3. J.P. Morgan Asset Mgmt., U.S., 34,983.0, 39,111.0

4. ING Real Estate Investment Mgmt., The Netherlands, 30,790.6, 88,507.5                           

5. AEW Capital Management, L.P., U.S., 27,639.4, 45,067.2