BALTIMORE, OCT. 22 -- A top AIDS researcher was ordered by a federal judge today to pay $12,000 in fines and perform 1,750 hours of unpaid research for steering $11,710 in business from the National Cancer Institute in Bethesda to a private laboratory where his wife was a stockholder and employee.

U.S. District Judge John R. Hargrove agreed with prosecutors that it would be more beneficial to society for former institute researcher Syed Z. Salahuddin, 49, to continue his work in AIDS-related viruses than to be imprisoned. Salahuddin could have been sentenced to a maximum of two years.

Defense attorney Seymour Glanzer said Salahuddin has already begun voluntary research on chronic fatigue syndrome, known as CFS, a disorder caused by a virus similar to those found in AIDS and herpes.

Salahuddin, now at the University of Southern California, worked with Robert C. Gallo, one of the nation's leading AIDS experts at the National Cancer Institute. Salahuddin, along with Gallo and others, has been credited with helping discover the human immunodeficiency virus that causes AIDS.

Prosecutor Dale P. Kelberman said he had received letters from medical scientists throughout the world praising Salahuddin's research.

"His scientific achievements ought to be considered" in keeping him out of prison and in the research field, Kelberman said.

Hargrove said Salahuddin "contributed quite a bit to mankind" but succumbed to crime "in a moment of weakness."

Salahuddin pleaded guilty last month to conflict-of-interest charges, admitting that in exchange for steering institute business to Pan Data Systems laboratory in Rockville, where his wife worked, the laboratory paid $6,000 to paint his house and paid off a $6,737 second mortgage on the house.

Victor Kubli, 27, former owner of Pan Data Systems, also pleaded guilty to paying an illegal gratuity in the case. He is scheduled to be sentenced Nov. 11.