Berkshire Hathaway Takes Top Spot in AM Best's Largest Insurer Ranking by Nonbanking Assets, UnitedHealth Group Retains Lead by Net Premiums Written.

Berkshire Hathaway has taken the top spot in AM Best's ranking of the world's 25 largest insurance companies by nonbanking assets, with $1.15 trillion. UnitedHealth Group retains its top spot by net premiums written for the 11th straight year, with a 6.2% increase to $308.8 billion. Allianz SE drops to second place, while China Life Insurance, Ping An Insurance, and Prudential Financial remain in the top five.