Traffic on U.S. airlines fell 7.1 percent in October compared with a year before, the carriers' weakest October since 2003, government researchers said Thursday.
It marked the eighth straight monthly decline from the year before, and traffic was down 2.6 percent for the year through October.
But airlines also cut the number of flights by 9.6 percent in October, and occupancy on domestic flights hit a record for the month. The average U.S. flight in October was 79.8 percent full, up from 78.5 percent in October 2007.
Southwest Airlines Co. continued to carry more domestic passengers than any other U.S. airline.
Researchers at the Bureau of Transportation Statistics said the number of passengers flying on U.S. airlines in October fell by 4.6 million, to 59.6 million.
For the first 10 months of the year, U.S. airlines carried 630.1 million passengers, down from 646.9 million in the same period of 2007. That was a decline of 3.3 percent in domestic passengers and an increase of 2.6 percent in international passengers.
The bureau said Dallas-based discount carrier Southwest carried 86.5 million passengers in the first 10 months of the year, more than any other U.S. airline, while AMR Corp.'s American Airlines carried the most international passengers.
Although Southwest carried the most passengers, bureau figures show that American, with longer flights, had a larger share of the domestic air-travel market as measured by miles flown by paying customers. That's a commonly used measure of airline traffic.
American's market share from November 2007 to October 2008 was 14.5 percent, followed by Southwest at 12.8 percent and UAL Corp.'s United, at 11 percent.
But American probably has already been knocked off the top spot.
Delta Air Lines Inc. and Northwest, which Delta bought last year, would have controlled 17.1 percent of the market if they had been a single airline during that span.
Government figures also show how carriers can dominate at their hub airports.
In October, American controlled 73.9 percent of the market in Dallas-Fort Worth and 71.6 percent in Miami. Delta had 53.7 percent in Atlanta, and Continental Airlines Inc. topped 50 percent at Houston and Newark, N.J.
The busiest airport remained Atlanta Hartsfield-Jackson International, although Miami was tops for boarding international passengers on U.S. carriers in the first 10 months of the year.