Excerpt: The tangled web of insurers and the brokers who deliver them billions in premiums from Corporate America is being deciphered faster and faster. .... On Nov. 11, the Labor Dept. told BusinessWeek Online that it is investigating whether insurers are paying improper fees to brokers and how those fees are being disclosed to the federal government. It's the incestuous relationship between big underwriters and their preferred brokers that troubles some benefits advisers.  MORE >>