BDM International Inc., a diversified professional services firm, had record revenues and income during 1981, according to President Earle C. Williams.

The McLean-based company posted profits of $3.2 million ($1.45 a share), a 16 percent increase over $2.8 million ($1.45) in 1980. Revenues grew 6 percent to $88.2 million from $83 million in 1980.

Fourth-quarter earnings were $1.05 million (48 cents) compared with $867,000 (37 cents) a year earlier, as revenues moved up to $24.1 million from $24 million in 1980.

Fourth-quarter results reflect a change in accounting that decreased revenue for the period by $79,000. The change does not affect the annual results, company officials said.

BDM announced an increased 17-cents-a-share dividend, payable April 1 to owners of record March 22.

Tesdata Systems Corp. posted higher revenues but lower earnings for the fourth quarter of 1981 and a loss for the year.

For the latest quarter, Tesdata earned $202,000 (16 cents a share) compared with $359,000 (27 cents) for the comparable period of 1980. Revenues climbed to $5.2 million from $4.7 million the year before.

For all of 1981, Tesdata lost $231,000 on revenues of $18.9 million compared with profits of $688,000 (53 cents) on revenues of $18.6 million during 1980.

Richmond-based Owens Minor Inc.'s profits leaped to $927,000 ($1.07 a share) during its third quarter ended Dec. 31 from $350,000 (41 cents) a year earlier.

Sales increased to $50.2 million from $38.5 million.

For the nine months, the hospital-supply company's profits were $2.47 million ($2.86) compared with $1.02 million ($1.20). Sales increased to $143.7 million from $111.1 million.