The Federal Home Loan Mortgage Corp. (Freddie Mac) yesterday reported net income of $208 million in 1985, the first year the federally chartered company was subject to taxation.

Freddie Mac said that before taxes and a one-time gain of $10 million from a special debenture transaction, its income was $362 million, a 36 percent increase over $267 million in 1984.

Post-tax earnings represented $12.51 a share of outstanding participating preferred stock, owned principally by savings and loans, and $197.40 a share of common stock, owned by the 12 Federal Home Loan Banks, Freddie Mac officials said.

Freddie Mac reported that it purchased $44 billion worth of mortgage loans, twice the number it bought in 1984, while it also sold increased amounts of mortgage securities. "Because of our record-setting mortgage purchase volume in 1985, this year became Freddie Mac's best in its 16-year history," said Leland C. Brendsel, acting president.

*MICROS Systems Inc., a developer and manufacturer of electronic information systems, reported continuing red ink in the second quarter ended Dec. 31, with a net loss of $538,800 (11 cents a share).

The loss compares with $16,700 lost in the three months ended Dec. 31, 1984.

The net loss for the year to date was $589,200 (12 cents), compared with net income of $131,600 (3 cents) for the first six months of fiscal year 1985, the company said. MICROS Systems, headquartered in Beltsville, attributed this year's losses to increased salary costs, product-marketing expenses, consulting and temporary services.

*Halifax Engineering Inc. of Alexandria, which provides technical services primarily to the federal government, reported profits of $27,000 (2 cents a share) in the third quarter ended Dec. 31, compared with a loss of $126,000 (11 cents) for the same period a year ago.

The earnings came on third-quarter revenue of $6.8 million, compared with $6.9 million the year before.

Revenue for the nine months in the year to date totaled $20.9 million in 1985, down from $22.3 million in 1984, the company said.

*C3 Inc., a Reston-based manufacturer of mini and microcomputer products, reported a loss of $335,000 (3 cents a share) in its third quarter ended Dec. 31, after earning $742,000 (8 cents) in the same period a year ago.

Revenue declined 43.1 percent during the quarter to $11.2 million from $19.7 million in the comparable period a year ago, the company said.

The company attributed the decrease in revenue to a "slowdown in delivery orders under existing contracts," a slowdown it said was primarily caused by the fact that the federal budget for the fiscal year has not been approved.

*Washington Homes Inc., a major area builder, more than doubled its net income in the fiscal 1986 second quarter, reporting profits of $1.7 million (59 cents a share), compared with $627,000 (23 cents) in the same period a year ago.

The company said net earnings for the year to date -- the six months ended Jan. 31 -- totaled $3.2 million ($1.14), compared with $1.4 million (50 cents) in the first half of fiscal 1985.

First-half sales climbed 14.3 percent, from $30.1 million to $34.4 million.