It described the results of the 98 pension funds, with assets of around £44 billion, as 'outstanding'. But councils were slightly behind private sector UK pension funds, which returned 17.7%.
Over the past 10 years councils are ahead of the private sector with an average return of 14.2%pa against 13.9%. This is because they were less exposed to the property price slump, WM says.
In real terms the return achieved by council funds was 15.2%, which outstrips the average performance over the past 10 years of 10%.