Unless the Federal Home Loan Bank Board and its insurance agency, the Federal Savings and Loan Insurance Corp., act soon, Guardian Federal Savings and Loan Association of Silver Spring may find itself at a point of no return.

While Guardian's net worth continues to deteriorate, the bank board apparently hasn't yet decided to approve a merger with Washington Federal Savings and Loan of the District.

The two S&Ls announced in early January that they had agreed to merge and that they expected a decision from the bank board within six weeks.

The FSLIC actually had given Guardian the choice of finding a merger partner by Jan. 4 or having the agency conduct a supervisory merger.

Guardian's current status can't be determined. Its chairman, Richard Bernstein, did not return calls to his office.

In any event, as a federally insured S&L, its deposits are insured up to $100,000 for each account.

Guardian came under close scrutiny after it lost $1.4 million in the first six months last year and watched its net worth dwindle to $3.5 million. At the same time, its reserve ratio had fallen to 2.7 percent--considerably below the standard set by regulatory authorities.

If Guardian had continued to experience losses at the same rate in the second half of 1981, it would have lost about $3 million last year. But with the industry experiencing its worst earnings performance since World War II, Guardian actually lost close to $3 million in the second half last year, say industry sources. What's more, its net worth, a key measure of profitability, was below $1 million at the end of the year, the same sources say.

Actually, the nation's 4,000 federally insured savings and loan associations lost a record $5 billion last year and several have since been absorbed either in supervisory mergers or mergers in which FSLIC financial assistance was required. In fact, the Bank Board reports 87 merger applications were acted upon through the first three months of this year. Of that total, 46 were voluntary mergers, 32 supervisory, and nine conducted with FSLIC assistance.

Although Guardian is a Maryland-chartered S&L, its executive offices and one of its branches is located in the District. Normally the Bank Board approves an interstate merger only after efforts to find an intrastate merger partner prove fruitless. Regulations bar interstate branching, but Guardian was permitted under a grandfather clause to retain its Dupont Circle office, which opened in 1955.

And although the Bank Board reportedly attempted to find a merger partner for Guardian in Maryland, the Atlanta Federal Home Loan Bank has recommended approval of the Washington Federal-Guardian merger application. However, no action has been taken at Bank Board headquarters here.

Washington Federal Chairman James Harris declined to discuss the matter beyond acknowledging that he was told the application had been recommended for approval some time ago by the Atlanta Bank Board.

Harris also acknowledged that Washington Federal has since asked the Bank Board for financial assistance to acquire Guardian. When asked why, he would say only that it's normal to request that type of assistance once the target merger date has passed. Asked if Guardian's situation had worsened, Harris replied: "I'm not going to comment on financial matters."

Meanwhile, Bank Board officials in Washington gave no indication when the merger application might be considered. It's possible that the sheer volume of applications requiring action by the Bank Board is holding up a decision on the Guardian-Washington Federal application.

That and two other applications from Washington-area S&Ls are "still in the hopper," remarked a Bank Board spokesman. "When something will happen is not clear at all. Hopefully it won't be much longer. They're all handled in due course."

Meanwhile, industry sources say Guardian can't afford to wait much longer for the bureaucratic wheels to run their course.