Top U.S. pension fund Calpers is sticking with commodities, an asset class known for volatile markets and returns, despite finding hedge funds too costly to work with, a spokesman said on Tuesday.

The California Public Employees' Retirement System, or CalPERS, provides retirement benefits to members and is the nation's largest public pension fund.

But its decision to quit the powerful Calpers - America's largest public pension fund with $256 billion of assets under management - could presage much larger problems for the system as it battles ...

CalPERS has entered into a five-year agreement with CVS Caremark, who will provide outpatient prescription drug benefits for about 587,000 members enrolled in basic or Medicare HMO or PPO plans.