A group of insurance companies associated with Guggenheim Partners LLC provided at least $300 million to help the firm’s chief executive and co-investors buy the Los Angeles Dodgers for a record $2.15 billion in 2012—an unusual arrangement that drew scrutiny from regulators before they eventually concluded that nothing was amiss.

Now the CEO is going public with an even more unusual arrangement he said is designed to protect policyholders and eliminate any potential conflicts of interest: He said he and a group of business...