William Moulton Inglis, a Chantilly man who once held top security clearance as a computer expert for the Defense Department, was convicted in federal court here yesterday of conspiring to produce and distribute obscene films and slides of young boys for an international child pornography business.

A jury deliberated for 7 1/2 hours over two days before concluding that the films, which were distributed in Europe and the U.S., were obscene and that Inglis was part of a conspiracy.

The jury also found Inglis guilty of 20 other charges of using the mails and an airline as part of an interstate mail order business in connection with obscene materials and of taking three boys from Baltimore to Northern Virginia for prostitution. He was acquitted of taking boys to Florida for prostitution.

Inglis, 35, who holds two master's degrees from the Massachusetts Institute of Technology, and who held a $33,000 job with the Defense Communications Agency, could be sentenced to up to 110 years in prison. Judge Frank A. Kaufman set Nov. 3 for sentencing.

Inglis resigned shortly after his arrest and has been jailed since, unable to post $150,000 bond, according to his attorney.

Prosecuting attorney Marsha Ostrer said Inglis was secretly the "lieutenant" in an international child pornography ring.

Defense attorney Parker Smith argued that Inglis was only involved because he was helping his friends and wanted companionship.