The U.S. Postal Service last week awarded new contracts with seven air carriers to transport mail. The largest awards went to American Airlines and Continental Airlines.

American Airlines on Sept. 20 signed a 5-year service agreement potentially worth $500 million, the largest single contract ever awarded to its cargo division, American said in a statement.

To accommodate the requirements of the previous USPS contract in 2003, American completely re-engineered its mail processes. As a preferred carrier of the Postal Service, American carries more mail than any other passenger airline. It is the world's largest airline.

"We have a strong relationship with the Postal Service and are pleased to have been selected as one of seven preferred carriers to participate in the new five-year agreement," said Dave Brooks, president of American Airlines Cargo Division.

Continental Airlines said Monday it inked a $258 million, five-year mail contract effective Sept. 30 to carry Priority, First Class and Express mail products within the United States and Puerto Rico. Continental will be the second-largest passenger airline carrying mail; it is the world's fifth-largest airline.

"We are celebrating our 72nd anniversary of high-quality, uninterrupted service for USPS. It is our largest cargo customer, and the new contract is icing on the cake," said Rick Banks, Continental's managing director of postal affairs.

Other carriers participating in the five-year deal are US Airways, JetBlue Airways, Midwest Express, ATA Airlines, and Sun Country Airlines.

United, Delta and Southwest did not participate in or were not awarded contracts.