Corporate use of derivatives might drop as a result of FAS 133, which was designed to expand accounting of derivative and hedge instruments, according to a study by Greenwich Associates. Although 73% of the companies surveyed said they didnt expect the regulation to affect their use of derivatives, 27% said it would. Those companies said they would cut back their use of more complex derivatives. FAS 133 requires that derivatives used for hedging risk be put on the company balance sheet at fair market value, which some executives fear could cause earnings volatility and affect stock prices. The study also found that although full compliance with FAS 133 is mandatory by June 30, only 35% of treasury professionals and 40% of U.S. asset managers said they were compliant by the end of 2000.