Mortgage-bond insurer MBIA (MBI) obtained the necessary approvals from senior debt holders to make National Public Finance Guarantee the "restricted subsidiary," taking the place of its parent company in legal proceedings.

This move is considered MBIA's way of reducing risk stemming from the dispute with Bank of America (BAC) over insured mortgage debt.

By asking senior-note holders to name the National Public Finance subsidiary as the "restricted subsidiary," analysts believe the mortgage-bond insurer is exercising legal options related to the firms' ongoing dispute about MBIA-insured Countrywide mortgage securities.

BofA made its own play recently, offering to buy all of MBIA's outstanding 5.70% senior notes due in 2034.