Top U.S. transportation officials have embarked on a two-week trip around the world to hear the complaints of foreign governments about the current U.S. review of fare-setting activities by the International Air Transport Association.

The whirlwind schedule includes diplomatic consultations on a regional basis in Bogota first, then Brussels, Nairobi and Manila. At issue specifically is the Civil Aeronautics Board's proposed withdrawal of U.S. antitrust immunity from IATA's rate-setting functions, at least as it affects travel to and from the United States. IATA is the trade organization of 103 world airlines.

"These will be government-to-government talks, but on a multilateral basis," James R. Atwood, deputy assistant secretary of State for transportation affairs, explained.

One major purpose is to make sure every foreign government that wings it has a change to talk to U.S. officials, including CAB policymakers who have taken the brunt of criticism for the CAB investigation into IATA's practices.

But Atwood says the consultations also will give the U.S. participants a chance to explain more fully what is being proposed, both its legal and policy contexts. There is some misunderstanding worldwide that the proposed U.S. action would affect agreed-on air fares between non-U.S. points, instead of just travel to and from the United States, Atwood said. The trip also will aid the participating executive agencies in formulating the views they will take in the CAB proceeding, he added.

In May, the CAB granted temporary approval to IATA's proposed restructuring - permitting airlines to join its trade-association activities without joining in its fare setting - while it continued to decide whether the rate-setting activities should continue to receive antitrust immunity.

Top CAB officials, including Chairman Marvin S. Cohen, director general of international and domestic aviation Michael E. Levine and general counsel Philip J. Bakes, are participating in the talks with foreign officials this week and next, along with Atwood and other State, Justice and Transportation Department officials.

In a related development, Sen. Howard W. Cannon (D-Nev.), chairman of the Senate Commerce Committee, announced that he had rescheduled hearings on his legislation to make the furtherance of competition in international aviation a U.S. goal by statute. The hearings are scheduled for late August in Las Vegas during the congressional recess. Hearings scheduled for next week were postponed, he said, at the request of the CAB, State and DOT because of the consultations.