The administration of Maryland Gov. Harry Hughes estimated in August that losses in the state's large crippled savings and loans would exceed $177 million, according to a document that Hughes gave to a private meeting of Maryland's congressional delegation yesterday.

The document -- a rare official indication of the state's financial exposure from an administration that has resisted public estimates -- said the losses were "far in excess of the amount" of money in an insurance fund the government maintains to cover such losses.

In his Aug. 14 letter, Assistant Maryland Attorney General Francis X. Pugh also wrote, "It would seem unfair for the taxpayers of Maryland to have to pay these losses."

Pugh's letter was presented at the end of an hour-long meeting held at the U.S. Capitol to discuss the state's six-month thrift crisis. At the meeting, Hughes defended his administration's handling of an October 1984 memorandum that warned of questionable business dealings by some savings associations. Since the memo was first publicized Saturday, the governor has been criticized by thrift depositors and members of the General Assembly for not acting aggressively enough once he received it.

"He said he did not feel the memo was of great moment," said Rep. Parren J. Mitchell, a Baltimore Democrat who initiated what he described as the "full-scale briefing" by Hughes.

One participant in the meeting, which was conducted in a room guarded by two police officers, described the atmosphere there as tense. The group included Reps. Michael D. Barnes, a Montgomery County Democrat, and Barbara A. Mikulski, a Baltimore Democrat, who recently opened campaigns for the same U.S. Senate seat coveted by Hughes, also a Democrat.

"The mood was certainly not a good one," said Rep. Roy P. Dyson, a Democrat from the Eastern Shore. Dyson said that last week, after the Maryland legislature narrowly approved the sale of three thrift associations to Chase Manhattan Corp., "I was breathing a little sigh of relief.

"Today's meeting took that sigh of relief away from me," said Dyson. "The fundamental underlying mood was 'How did we get into this situation?' This situation could turn into a nightmare."

The state's thrift industry crisis already has been a financial nightmare for tens of thousands of depositors and a political nightmare for Hughes, one that took a disturbing twist with the disclosure of the 1984 memo written by George W. Liebmann, a Baltimore lawyer who was a trusted adviser to Hughes for six years.

Hughes and Mitchell told reporters after the meeting that the governor apprised the delegation of the origins of the thrift crisis and its recent chronology, including the administration's successful attempts to nudge many savings associations into the system of federal deposit insurance. Municipal Savings and Loan of Towson became the 32nd Maryland thrift to qualify for federal insurance yesterday.

Despite such progress, some in the delegation cited Pugh's letter as evidence that the state government is by no means out of the woods.

The letter by Pugh, who also attended the meeting yesterday, was presented as part of Hughes' request that the Maryland delegation seek a change in federal tax law to exempt the state government from paying $15 million to $20 million in back taxes that are due on the $177 million thrift insurance fund.

The insurance fund and an $89 million central reserve fund are now controlled by the Maryland Deposit Insurance Fund, a state agency that replaced the old private Maryland Savings-Share Insurance Corp. (MSSIC) when the industry nearly collapsed in May.

MSSIC was formed in 1962, five years after the cutoff date at which the Internal Revenue Service grants an exemption to certain taxes on private thrift insurance.

Only $56 million is readily available in the old MSSIC insurance fund. Several thrift associations already have borrowed $101 million, and the remaining $20 million is in escrow to offset expected losses at Old Court Savings & Loan of Baltimore.