The Anti-Defamation League of B'nai B'rith said yesterday the McLean-based Dynalectron Corp. pressured a group of helicopter pilots and maintenance men to convert to Islam when the signed up for a company operation in Saudi Arabia.

The firm, which provides technical services to the U.S. government and private industry, denied it had exerted such pressure on any of its employes. An official of ITS International Inc., a wholly owned subsidiary of Dynalectron, acknowledged that 31 Dynalectron employes hired for the Saudi Arabia operation converted to Islam, but said they did so voluntarily.

The Anti-Defamation League said Dynalectron set up Moslem conversion programs for the workers -- many of them professing Christian beliefs -- before they went to Saudi Arabia for fire-prevention duty during the October 1978 pilgrimage to Meca, the holiest place in the Moslem world.

Under Saudi Arabian law, which is heavily influenced by the state Islamic religion, only Moslems can enter the holy area of Mecca.

"We fully respect the religious requirements and practices connected with Mecca," said Abraham H. Foxman, associate national director of the league in New York. "But for the Dynalectron firm to recruit non-Moslems and then arrange their religious conversion is offensive and un-American."

"There was no coercion whatsoever of the 31 employes," said Marvin Zediker, vice president of administration of ITS International Inc.

Zediker acknowledged in a statement that "the Saudi Arabian government has imposed strict Moslem requirements for helicopter and service personnel who are to be in the holy area."

Asked if he thought it was unusual for 31 company employes to convert to the Moslem faith, he said: "I don't find it unusual for there to be 31 Moslems in the United States."

The controversy grew out of a court suit filed against Dynalectron by one of the six pilots recruited for the job, which involved preventing the outbreak of fires in the heavily populated encampments at Mecca during the pilgrimage.

The pilot, Wade Kern, is suing Dynalectron for $10,000 in U.S. District Court in Fort Worth. His attorney said the pilots were warned "that they could face death if they went to Mecca without becoming sincere and bona fide converts to Islam."

Dynalectron's Zediker called Kern's suit "a case of sour grapes."