(a) Limitations.— When air transportation is provided between the United States and a foreign country both by aircraft owned or operated by an air carrier holding a certificate under chapter
411 of this title and by aircraft owned or operated by a foreign air carrier, the United States Postal Service may not pay to or for the account of the foreign air carrier a price for transporting mail by aircraft between the United States and the foreign country that the Postal Service believes will result (over a reasonable period determined by the Postal Service considering exchange fluctuations and other factors) in the foreign air carrier receiving a price for transporting the mail that is higher than the price
(1) the government of a foreign country or foreign postal administration pays to air carriers for transporting mail of the foreign country by aircraft between the foreign country and the United States; or
(2) determined by the Postal Service to be comparable to the price the government of a foreign country or foreign postal administration pays to air carriers for transporting mail of the foreign country by aircraft between the foreign country and an intermediate country on the route of the air carrier between the foreign country and the United States.
(b) Changes.— The Secretary of Transportation shall act expeditiously on proposed changes in prices for transporting mail by aircraft in foreign air transportation. When prescribing those prices, the Secretary shall consider
(1) the prices paid for transportation of mail under the Universal Postal Union Convention as ratified by the United States Government;
(2) the price-making elements used by the Universal Postal Union in prescribing its airmail prices; and
(3) the competitive disadvantage to United States flag air carriers resulting from foreign air carriers receiving Universal Postal Union prices for transporting United States mail and national origin mail of their own countries.
