A Maryland judge, rejecting a last-minute effort to sell the insolvent First Maryland Savings and Loan Association, today gave the state the right to begin disposing of the Silver Spring thrift's assets and to repay fully most of the depositors within six weeks.

Baltimore Circuit Court Judge Joseph H.H. Kaplan ordered the thrift into receivership, which is a legal condition akin to bankruptcy, after rejecting pleas by a depositors group and lawyers for First Maryland's former officers to delay the action so they could line up a buyer for the crippled association. The depositors contended that selling the thrift would free deposits more quickly than the time-consuming liquidation of First Maryland's assets.

"I can't deprive people of their funds based on pie in the sky," Kaplan said in open court, after a private briefing in his chambers about a sale that depositors and stockholders had worked feverishly to arrange before today.

"The chance of First Maryland being taken over as an entity is slim and none," the judge said after recounting the thrift's considerable financial ills. "It makes sense for the court not to gamble with depositors' and taxpayers' money."

If the state's experience with paying back depositors at another thrift in liquidation, Old Court Savings & Loan of Baltimore, is any guide, the return of deposits to First Maryland customers promises to be a bureaucratic headache. The planned liquidation of First Maryland's far-flung assets probably will last at least until 1990, largely because 86 percent of the association's accounts are larger than the sums that can be repaid this year.

The Maryland Deposit Insurance Fund (MDIF) plans to use approximately $70 million this year to fully repay 10,577 small depositors and all 6,313 holders of individual retirement accounts, and give $5,000 to each of First Maryland's largest account holders.

MDIF Director Melville S. Brown said the initial depositor payments will be primarily funded by $50 million from an insurance fund that the agency controls and an additional $15 million authorized by the General Assembly last winter.

The 7,181 depositors with more than $5,000 each in First Maryland have a combined total of $245 million in their accounts. They will be repaid during the next several years on a pro rata, per account basis as the thrift's assets are sold off. MDIF insures each account up to $100,000.

Under the terms of the receivership, deposits will not earn interest as of today. Kaplan previously had cut the interest rate to 5 1/2 percent.

Certificates of deposit also will be considered as having matured today, which means that each account balance will be equal to the principal plus interest to date.

Only mortgage escrow accounts will continue to earn interest, at an annual rate of 3 percent.

State officials had tried for six months to arrange the sale of First Maryland to Yorkridge-Calvert Savings and Loan of Baltimore, but the plan fell through when federal officials refused to approve the acquisition.

Kaplan's decision was hailed by aides to Gov. Harry Hughes, a U.S. Senate candidate who viewed the resolution of First Maryland's problems as the last remaining step to resolving the state's 13-month savings and loan crisis. Kaplan's order sets the stage for the full repayment of 70 percent of First Maryland's 24,071 depositors by August, according to state officials.

Alan Ehrlich, a First Maryland depositor who lives in Montgomery County, said he was infuriated by Kaplan's order.

"We're very upset," Ehrlich told reporters outside Kaplan's courtroom. "We have a positive, strong interest by some institutions in acquiring First Maryland."

Ehrlich and other depositor group leaders repeatedly declined to identify the prospective buyers of First Maryland, saying publicity would kill their negotiations to revive the S&L, where $282 million in deposits have been frozen since last August.

Thomas H. Maddux, a state cabinet secretary who helped negotiate the sale of several other distressed thrifts in the past year, said the financial institution on which the depositors had pinned their hopes was based in the mid-Atlantic region, but was not a serious contender.

For the first time in the saga of First Maryland, which began with the thrift's phenomenal growth in the early 1980s but turned sour amid depositor runs last summer, state officials offered the clearest details yet about the thrift's problems -- a giant tangle of bad loans, huge debts and lawsuits that prompted Kaplan today to compare it to Old Court, the large Baltimore thrift association that sparked the S&L crisis and is now being liquidated.

According to the MDIF, which is overseeing both thrifts, a review of First Maryland's books showed a $40 million loss in its real estate portfolio; $70 million in assets that generate no income; a pledge of healthy assets to cover a $40 million debt; $150 million in "unattractive" construction loans for projects across the country, and a need for $25 million to complete loans in progress.

Asked today whether a sale of First Maryland were still possible, Robert Winter, a Washington lawyer assisting MDIF, said: "When you're standing in a graveyard, there's no use pretending it's a disco."

In appealing to Kaplan to delay the receivership, H. Robert Erwin, a lawyer for a statewide depositors group, said that 19 large depositors who have $9 million in First Maryland were willing to pledge a portion of their deposits to assist a legitimate buyer of the thrift.

But Kaplan, who nine days ago had given Erwin and the depositors extra time to find a buyer, was not convinced.

Erwin "doesn't even have the $9 million pledge on line," Kaplan said. "That really leaves me very little choice" but receivership.