Federal thrift officials signaled yesterday that they are preparing to renegotiate the costly agreements the government signed with investors who took over failed savings and loans in 1988.

The deals, negotiated by the now-defunct Federal Home Loan Bank Board, have been widely denounced as a huge waste of taxpayers' funds. The deals' 10-year cost is currently estimated at $66.9 billion, not including an additional $4.5 billion in tax breaks to be reaped by the thrift investors. Last fall, Congress authorized borrowings of $22 billion to pay off the government's obligations early in order to save about $4 billion in the long run.

The 1988 deals involved the sale of 220 failed thrifts to 96 financial institutions and private investors, including some of the wealthiest people in the nation.

L. William Seidman, chairman of both the Resolution Trust Corp. and the Federal Deposit Insurance Corp., announced yesterday that he is transferring responsibility for overseeing the '88 S&L deals to the RTC, the agency created two years ago to dispose of failed thrifts. He also announced several changes in the RTC's structure and staffing.

The RTC has been weighing its options with regard to tightening up the agreements. In essence, it can either decide to buy back the troubled real estate and other items it is paying the thrifts high subsidies to hold, use the threat of doing that to get thrifts to agree to accept lower subsidy payments, or both.

"Renegotiation is certainly a possibility," said RTC spokesman Steve Katsanos. "If they don't want to do it, if you have the money, you can buy back the assets. And we've got the money."

"The organizational changes being made at the RTC will better position the RTC to take on a growing workload, including restructuring the 1988 {bank board} deals," said Seidman.

A recently completed consultant's report prepared for the Bush administration and Congress concluded that federal regulators did not give all those who bid on thrift purchases an equal chance to compete, driving up the overall cost of the cleanup.

Among the deals considered overly generous was the acquisition by Ronald O. Perelman, Revlon Group Inc. chief executive, of five thrifts merged into First Gibraltar Bank in Houston. First Gibraltar is to receive $5 billion in government assistance on a minimal capital contribution by its buyer. In its first year of operation, First Gibraltar reported a 44 percent return on its investment.

Gerald Ford, chairman of First Gibraltar, said he expects to negotiate changes with the RTC that are "viable for us and less costly for them. I expect all the other acquirers to do that."

Some Treasury officials and industry analysts have voiced fears that forcing contract changes could hurt the government's efforts to do business in the future and end up slowing sales of failed thrifts and their holdings.