In a final report of 1976 operations, International Bank of Washington has listed a net loss of $511,733 compared with restated 1975 profits of $863,047 (5 cents a share).

The financial services company posted record revenues of $8.3 million for 1976, a gain of 25 per cent from the previous year's level. The company also had record profits but they were eroded by the discovery of accounting problems at a subsidiary bank in the Bahamas and the sale of a controlling interest in Financial General Bankshares, a bank holding company.

IB chairman George Olmsted noted that discrepencies in the statements of Mercantile Bank and Trust Co., Ltd., of Freeport necessitated reserves of $7.5 million for possible losses. The sale of Financial General stock ordered by the Federal Reserve Board necessitated reserves for $5.4 million to cover a loss on the sale and income taxes.

Reviewing IB's major operations, Olmsted said:

Property and casualty insurance companies contributed $3.6 million of earnings compared with $214.000 in 1975, outperforming industrywide levels of recovery from two depressed years.

Life insurance earnings increased by 15 per cent to a record $1.8 million.

Industrial firms contributed earnings of $7.7 million, up 41 per cent from the previous year.

Finance, venture capital and leasing losses were reduced by 24 per cent to $914.000.

International operations were affected adversely by a $1.6 million provision for possible losses on loans purchased from a subsidiary, and the reserves for problems associated with Mercantile bank, now being liquidated.

Earnings for 1975 were restated to reflects a reversal of interest income on certain loans made by Mercantile. The loans which apparently were reported impropely on the Bahamas bank's books related to Florida land purchases, an IB spokesman said.

IB, meanwhile, has reported record profits for the first quarter of 1977 of $3.1 million (43 cents a share) compared with $2 million (28 cents) in the 1976 period.

Radiation Systems, Inc., a McLean antenna manufacturer, reported profits of $420,000 on sales of $3.5 million for the nine months ended March 31 compared with earnings of $260,000 and sales of $3.1 million the pervious year. Because of tax loss provisions, these earnings were covered only partly by income taxes; if fully taxed, RSI would have earned $345,000 (45 cents a share) compared with $135,000 (19 cents) a year earlier.

President Harry Letaw Jr. said his board of directors has authorized the purchase of up to 100,000 shares of RSI stock through Oct. 31. RSI's backlog of orders on March 31 was $3.3 million, off from $3.7 million a year earlier.

Washington Homes, Inc., a home builder based in Oxon Hill, reported that profits in the six months ended April 30 rose to $1.1 million (81 cents a share) from $784.720 (60 cents) in the previous comparable period. Revenues rose to $24 million from $17 million.