U.S. pressure appears to have led the Italian government to block the delivery to Iran of several Chinook helicopters and 15 cases of spare parts for other helicopters already delivered to that country.

News of the decision not to carry through with earlier plans to authorize the shipments came this morning from officials of the Agusta Co. which produces Boeing, Bell and Sikorsky vehicles in Italy under American license.

Agusta General manager Piero Fascioni was quoted as saying that the company's export permits had been "suspended" because of discussions between the Italian and American governments on the attitudes to be taken toward Iran. He stressed, however, that it was a temporary measure which did not mean that Italy had set an embargo.

In addition, Agusta officials were well aware that disregard of U.S. feelings on so sensitive a matter could have led to the revocation of the American licenses.

Although American officials insist it is an unrelated matter, informed Italian sources said they believed American displeasure might also jeopardize an Iraqi order of four Italian frigates built with General Electric turbines.

The U.S. government was dismayed with in March, the Italian government authorized the delivery to Iran of the helicopters and spare parts "for humanitarian reasons," for emergency use in parts of Iran that had been flooded and hit by earthquakes.