• W.R Berkley average operating margin for 2011-09-30 was 0%, a 0% decline from 2011-12-31.
• W.R Berkley average operating margin for 2011-12-31 was 0%, a 0% decline from 2012-03-31.
• W.R Berkley average operating margin for 2012-03-31 was 0%, a 0% decline from 2012-06-30.

Operating margin can be defined as operating margin measurement of what proportion of a company's revenue is left over after paying for variable costs of production such as wages, raw materials, etc.