Cordatum Inc., a Bethesda developer of computer software and educational videodisc systems, posted a net loss of $77,400 (2 cents a share) on revenue of $473,886 for the third quarter ended Sept. 30, compared with a loss of $32,523 (1 cent) on revenue of $320,707 for the year-previous period.

However, Cordatum President Merle C. Garvis said contract revenue rose 48 percent for the 1984 third quarter and that revenue for the nine months ending Sept. 30 had jumped 70 percent to $1.38 million from $812,301 for the same period in 1983.

PHH Group Inc. reported net income of $9.9 million (62 cents a share) for the second quarter ended Oct. 31, a 12 percent increase over last year's $8.8 million (56 cents), the company reported yesterday.

For the six months ending Oct. 31, the Hunt Valley, Md.-based diversified services company posted record net income of $19.3 million ($1.21) on sales of $304 million, compared with net income of $17.4 million on revenue of $265 million for the same period in 1983.

PHH operates a group of cost control management services, including aircraft fleet management and leasing.

Finalco Group Inc. said net income for the three months ended Sept. 30 was $425,000 (8 cents a share), compared with $383,000 (also 8 cents) in the 1983 period.

Finalco, a McLean-based company specializing in developing and marketing syndicated tax-advantage equipment leasing programs, said third-quarter revenue was $18.42 million, compared with $16.24 million for the 1983 period.

Bresler & Reiner Inc., a Washington real estate and home building firm, reported an increase in net income of 57 percent for the third quarter ending Sept. 30 over the same period last year. The company announced net income of $589,000 (53 cents per share), up from $375,000 (34 cents) last year.

For the nine months ended Sept. 30, the company reported net income of $2.3 million ($2.08) on revenue of $11 million, compared with net income of $963,000 (87 cents) on revenue of $10.6 million in the 1983 period. The company said interest income was higher in 1984, particularly interest on mortgages from the sale of land. Third-quarter revenue was lower in 1984 than the previous year because of a lower level of home building by the company.

Vector Automation Inc., a Baltimore company that manufactures and markets interactive computer systems and graphics terminals, yesterday reported sales of $1.8 million during the third quarter ended Sept. 30, compared with $1.76 million last year. But the company reported a loss of $186,704 (9 cents per share) during the third quarter as opposed to a net income of $165,381 (11 cents) last year.

For the nine months ended Sept. 30, the company reported revenue of $5 million, compared with $3.8 million for the same period in 1983. The net loss for the nine months was $404,179 (19 cents), up from $60,600 (4 cents) for the same period in 1983. The company said the losses were the result of costs incurred by expanding the sales force to cope with greater demand for turnkey computer systems for computer aided design and manufacturing. At the same time, the company said sales of graphics terminals were down slightly this year.

Old Dominion Real Estate Investment Trust, a Richmond trust, reported an increase in cash flow from operations for both its third quarter and nine months ended Sept. 30, while reporting a decrease in net income for the third quarter. Cash flow for the third quarter was up slightly to $360,704 (21 cents per share), from $316,922 (21 cents) last year. Cash flow for the nine month period was $1 million, up from $825,481 for the same period last year.

Income before gains on sales of investments amounted to $122,298 on rents of $1.8 million in the third quarter, compared with $161,813 on rents of $1.3 million for the third quarter last year. Net income for the third quarter was $122,941 (7 cents), a decrease from $168,664 (11 cents) last year.

The company said the results were slightly less than projected because of expenses associated with preparing apartment units for re-renting at higher rates at four recently purchased apartment complexes.