The Student Loan Marketing Association (Sallie Mae), the government-sponsored enterprise that buys student loans from lenders, reported that its profit rose 17 percent in 1990.

The Washington-based company's net income for the year was $300.9 million ($2.96 per share), compared with $257.6 million ($2.53) in 1989.

As of year-end, its assets -- mostly loans it purchased from their originators -- were $41.1 billion, up 16 percent from $35.5 billion at the end of 1989.

"Sallie Mae's 1990 performance resulted chiefly from continued very strong student loan purchase volume," said Lawrence A. Hough, president. "Most significantly, most purchases represented good core volume, coming from regular clients ... "

In the fourth quarter, Sallie Mae's net income rose 15 percent to $78 million, from $68 million in the same quarter a year earlier.

American Capital and Research Corp. of Fairfax said its profit in the quarter ended Nov. 30 rose 68 percent.

Net income in the quarter, the third of ACR's fiscal year, was $3.85 million (18 cents a share), compared with $2.29 million (15 cents) in the same quarter a year earlier. Revenue was $180.47 million, up 28 percent from $141.14 million a year ago.

ACR is a holding company with subsidiaries that provide environmental, engineering and other services. Chairman James O. Edwards said the company's results were helped by increased earnings of an Australian subsidiary and continued strong sales despite the economic downturn.

General Kinetics Inc. of Rockville said its profit more than doubled during the quarter ended Nov. 30.

The company's net income rose 141 percent to $436 million (44 cents a share), from $180.76 million (21 cents) in the same quarter last year. Revenue rose 25 percent to $5.3 million.

General Kinetics makes and sells high-security communications equipment, metal enclosures and equipment used in food processing.