NYT

.....In 1999, the lawmakers adopted the Gramm-Leach-Bliley Act, which broke down the Depression-era restrictions between investment banks and commercial banks. As part of a political compromise, the law gave the commission the authority to regulate the securities and brokerage operations of the investment banks, but not their holding companies.

In 2002, the European Union threatened to impose its own rules on the foreign subsidiaries of the American investment banks. But there was a loophole: if the American companies were subject to the same kind of oversight as their European counterparts, then they would not be subject to the European rules. The loophole would require the commission to figure out a way to supervise the holding companies of the investment banks.

In 2004, at the urging of the investment banks, the commission adopted a voluntary program. In exchange for the relaxation of capital requirements by the commission, the banks agreed to submit to supervision of their holding companies by the agency.