Sen Gaylord Nelson (D-Wis.) introduced legislation yesterday to give Congress more time to review major arms sales to foreign nations.

The dispute over the $1.2 billion sale of seven Airborne Warning and Control System (AWACS) aircraft to Iran, Nelson told the Senate, shows "the inadequacy of the present law."

In the face of congressional opposition, Nelson noted. President Carter last Thursday "temporarily defused the AWACS issue until Congress returns in September" by withdrawing the request and deciding to resubmit it in September. The existing 30-day limit for Congress to act on the sale would have expired Firday.

Nelson yesterday proposed extending the period for review of such sales from 30 calendar days "to 45 days in which Congress is in continuous ses.

Under present law known as the Nelson amendment, the President is required to submit to Congress any foreign military sale in excess of $25 million, wiht the Senate an House given 30 days to block the sale by concurrent resolution. Senate majority leader Robert C. Byrd (D.W. Va.), who urged the President to allow more time for the debate on AWACS for Iran, Saturday said he favored extending the 30-day deadline.

Nelson, who tried unsuccessfully in the past to extend the period, noted that the current 30-day limit applies whether Congress "is in session or not." During the last fiscal year alone. Nelson said, the United States "agreed to sell abroad military equipment and weapons worth over $14 billion," with insufficent time for Congress to consider the major foreign and military policy implications.

The State Department said yesterday it has not been asked by Iran to cancel the sale of the disputed AWACS radar system. Several Iranian newspapers reported that intention, as a result of delayed U.S. action on the sale.

Spokesman John H. Trattner said there has been no "official notification from Iran about the reported cancellation or withdrawal of the request," and "there has not been any change in the administration's commitment to provide the AWACS aircraft to Iran."