Coruscation

Covered bonds are pools of debt obligations that have been assembled by banks and sold to investors who receive the income generated by the assets. The bank that issues the bonds, meanwhile, retains the credit risk. If losses arise, the bank that issued the covered bonds must offset the loss with its own capital. That could push troubled banks closer to the edge.

If an asset in the pool defaults, a separate entity would be required to remove the assets from the bank's control. The assets would then be out of reach of the F.D.I.C. should the bank fail and the agency step in as receiver. The investors who bought the covered bonds would have first call on the assets, ahead of the F.D.I.C.

This structure would wind up bestowing a new form of government backing to the major banks issuing the bonds, raising the potential for losses at the F.D.I.C. insurance fund, which protects savers' deposits.

Equally troubling, the covered bond structure favored by the banks would let the pools invest in risky assets such as home equity lines of credit. These loans have been among the worst-performing assets out there. Covered bonds issued overseas, by contrast, typically consist solely of high-quality loans.

"The industry is trying to do an end run around the F.D.I.C.," said Christopher Whalen, publisher of the Institutional Risk Analyst. "This proposal is about restarting the Wall Street assembly line for selling toxic waste to investors."