Air passenger revenue of US Airlines fell by 4% in December 2009 compared with 2008 due to a 3% drop in passenger volume and a 2% drop the in average price to fly a mile, according to the Air Transport Association (ATA) of America.
The drop is the 14th successive decline in passenger revenue based on data from a sample group of airline carriers.
There has also been a sharp decline in trans-Pacific passenger revenue.
The year-on-year figures for 2009 reveal a decline of 18% compared with 2008, which is attributed to a 6% fall in passenger traffic and a 13% fall in the average price to fly a mile.
Cargo traffic, however, saw an upward swing in November 2009 with a 7% increase compared with 2008, considered due to international trade.
Domestic cargo traffic grew by 2% while international cargo volume grew by 11%, the first increase since July 2008.
The ATA is the industry trade organisation for US Airlines, which operate nearly 26,000 flights in 80 countries, using more than 6,000 aircraft to carry an average of two million passengers and 50,000t of cargo daily.