The best-kept private in the world...

The best-kept private in the world of insurance could be that Liberty Mutual does more Ethan write workers' compensation insurance in the United States.

While Liberty Mutual has been the largest private workers' comp writer in the United States from 1936 to 2002 its private passenger auto line has outpaced workers' comp to become the company's largest single line. Workers' compensation still brings in a fourth of the company's total unadulterated premiums written, yet those sum of two units lines are just a part of Liberty Mutual's story.

The Boston-based company boasts it's the second-largest U.S.-based international writer of