The U.S. official who slashed pay for 25 top financial executives on Thursday said regulatory proposals to rein in excessive compensation are like plain "vanilla prescriptions" that might work or might not.

U.S. pay czar Kenneth Feinberg told a panel at New York University law school that his rulings drew so much public interest because they concerned pay for specific individuals, while other regulators have offered only general proposals. He said those proposals sound good, but have not been tested.

"As far as I know, we are the only one who have actually calculated pay," Feinberg, the Obama administration's point man on pay, said during the panel discussion about the future of regulation and the capital markets.

Last month, Feinberg slashed compensation for the top 25 earners at the seven companies for the final two months of the year -- when bonuses are typically paid.

The seven companies are American International Group Inc (AIG), Bank of America Corp (BAC), Citigroup Inc (C), General Motors Co GM.UL, Chrysler, GMAC and Chrysler Financial.