American Realty Trust of Arlington yesterday reported reduced losses for the third quarter ended June 30, but losses much smaller than those suffered last year when the firm was the subject of a Securities and Exchange Commission suit which the government subsequently lost.

The trust announced losses of $203,105 (9 cents per share) on revenues of $1.1 million, compared with losses of $1.7 million for the same quarter last year.

For the nine months, American Realty's loss amounted to $407, 865 (18 cents) on revenues of $4.5 million, compared with a loss of $3.3 million ($1.49) on revenues of $3.8 million for the same period in 1976.

Commenting on the trust's operations, Thomas J. Broyhill, the company chairman, said American Realty has been negotiating with banks for a restructuring of its short-term debt.

"We are making progress towards a refinancing agreement which, if consummated, will greatly strengthen the trust's financial position and enable it to achieve an early return to profitable operations," Bryhill said in a statement.

Financial Security Group, Inc. of Washington reported profits of $1.9 million (64 cents a share) for second quarter ended June 30. This compares with an income of $815,000 (27 cents) for the corresponding 1976 period.

For the first six months, earnings were $3.0 million (99 cents), up 160 per cent over the $1.1 million (30 cents) reproted for the same period last year.

Federal Realty Investment Trust of Chevy Chase, Md., reported second quarter profits of $386, 788 (29 cnets a share) on revenues of $1.6 million. This compares with earnings of $231,374 (26 cents) on revenues of $1.4 million for the second quarter last year.

For the first six months of 1977, profits were $795,393 (59 cents) on revenues of $3.2 million, compared with $502,871 (59 cents) on revenues of $2.7 million last year.

American Finance Systems Inc., the Silver-Spring based firm which operates 400 loan offices in 23 states, poted net income of $2.152 million for the quarter ended June 30 (45 cents per share) on gross revenues of $21.52 million, compared with a net income of $556,000 (8 cents) on revenues of $21.75 million for the same quarter in 1976.

For the six months ended June 30, net income was $4.124 million (86 cents) on revenues of $42.06 million, compared with income of $1,18 million (18 cents) on revenues of $42.56 million for the same period last year.

Tesdata Systems Corp., the McLean based firm which makes hardware computer performance measurement systems, reported profits for the second quarter ended June 30 of $485,942 (41 cnets a share), up 43 per cent over earnings of $338,821 (36 cents) for the second quarter last year. Revenues for the second quarter were $3.44 million, up 39 per cent over revenues of $2.48 million for the same period last year.

For the first six months, net earnings were $879,256 (79 cents), compared with $564,665 (64 cents) last year.

Capital Mortgage Investments of Chevy Chase announced second quarter profits of $674,419 (40 cents), compared with earnings of $718.747 (43 cents) for the same period in 1976. For the six months ended June 30, the real estate investment trust sustained a loss of $654,757 (39 cents) which compares to income of $718,747 (43 cents) for the same period last year.

Dynalectron Corp. of McLean announced a return to profitability during the second quarter of 1977, though the improvement was below company expectations and inadequate to offset fully the first quarter loss.

Net profits for the second quarter were $66,000 (1 cent a share) on revenues of $69.5 million, compared with $580,000 (8 cents) on revenues of $46.6 million last year. For the first six months of 1977, the net loss is $136,000 (3 cents) on revenues of $124.6 million, compared with earnings of $1.222 million (16 cents) on revenues of $92.9 million last year.

Logetronics Inc. of Springfield, Va., reported second quarter income of $97,000 (10 cents a share) on sales of $3.84 million, compared to profits of $20,000 (2 cents) on sales of $3.24 million for the second quarter of 1976. For the six months ended June 30, income was $265,000 (27 cents) on sales of $7,44 million compared with income of $106,000 (11 cents) on sales of $6.35 million the previous year.