A leading federal official warned today that the savings and loan industry may not rebound from its current slump unless it adapts to the deregulation problems policies pushed by Congress and government regulators.

"Improvements in economic indicators should not be taken as a return to comfortable conditions, to lead us into a false sense of security about the future," said John Dalton, one of three members of the Federal Home Loan Bank Board.

Although Dalton predicted that by the first quarter of 1981 the inflation rate would drop to 9.5 percent and that mortgage rates would hit 11.5 percent, this year will be the "worst year in the last 50" for the nation's housing industry, whose fate is directly tied to that of the S&Ls.

In remarks prepared for the annual meeting of the Virginia Savings and Loan League here, Dalton said that despite competition from other institutions and government sources. S&Ls "will and must continue to be the primary source of residential home financing."

But with the passage earlier this year of omnibus banking legislation, the industry no longer can operate "isolated from the pressures of the marketplace," he said. The legislation is designed to lift regulations over the industry gradually and, in particular, Regulation Q, which governs interest rates.

Dalton told the S&L executives to take advantage of the opportunity to evolve into centers for "family financial services" next year, when S&Ls can expand their consumer lending authority and enter credit card markets. Historicially, the S&L industry has fought most deregulation proposals.

Those developments will enable S&Ls to gain more savings funds "to better equip this industry to finance the anticipated demand for home loans in the decade of the '80s," Dalton said.

He predicted that through the 1980s "mortgage rates on the average will be in the range of 10 to 11 percent."

"To meet the home financing needs, S&Ls will have to make greater use of creative financing techniques, and the current earnings squeeze and the reduced flow of savings capital must be reversed," he said in prepared remarks. r

Dalton was referring to instruments such as renegotiable rate mortgages, which allow S&Ls and borrowers to revise mortgage interest rates every three, four or five years.

Although Dalton said he is "optimistic" about the long-run economic picture, he warned of difficult times for the industry if inflation is not reduced. He said the coming year "will test the ability of the S&L industry" to meet the current adverse situation.

"Unless inflation is brought under control, the future of the savings and loan industry and our nation, not just in the short term, but on a long-range basis, is in serious jeopardy," Dalton said.