Conventional state insurance regulation protects policyholders by requiring companies to set aside enough of the premium money they take in to build reserves to pay all future claims. Companies are also required to maintain a healthy surplus, and regulators can make them stop selling new policies if they fall too far short.

When the life insurers secure their policies through special-purpose vehicles, however, they can do so without building up a body of liquid, cashlike reserves, as prescribed by regulators.

Instead, they offer some form of collateral, like a letter of credit, to stand behind the policies. Some regulators said there were cases in which the collateral was inadequate and would not have been admitted under the usual regulatory standards.

Data compiled by SNL Financial, a data and news company, shows that the practice of securing life policies through a wholly owned subsidiary has grown sharply in the last five years. In 2006, the companies SNL surveyed used such subsidiaries for 31 percent of the policies they reinsured; by 2011, it was up to 45 percent.

SNL also found that while the practice was very popular at some companies, others did not use it at all. The American International Group used subsidiaries for nearly 80 percent of the life policies that it reinsured in 2011, for instance, while Northwestern Mutual used only unaffiliated reinsurers, where the terms would be set in an arms’ length transaction. Still others, like State Farm, were not reinsuring their life policies as of 2011.

New York Life, a modest user of affiliated reinsurers at 15 percent, submitted a written comment letter to the panel, warning of “a system that encourages companies to circumvent statutory reserving standards by using complex structured transactions.” It called for “strong regulation” that would allow only “clean, unconditional collateral” to backstop the reinsured policies.

New York Life also said that after artificially lowering their costs through the complex transactions, some companies were coming back to market and selling new policies to consumers at low prices.