United Continental Q4 passenger revenue may rise

* Unit revenue seen up vs. year ago

* Filled seats seen softer in Atlantic region

ATLANTA Dec 22 (Reuters) - United Continental Holdings Inc (UAL.N) on Wednesday said it expects passenger revenue to rise in the fourth quarter.

The holding company for United Air Lines and Continental Airlines expects passenger revenue per available seat mile, a measure also called unit revenue, to rise 9.75 percent to 10.75 percent in the fourth quarter, including feeder aircraft.

The company issued its forecast in a filing with U.S. securities regulators.

The carrier's update showed that load factors, or percentage of seats filled, at United and Continental were expected to be weaker in the Atlantic and Latin America regions compared with the fourth quarter a year earlier.

Earlier this month, Delta Air Lines (DAL.N) cited weakness in the Trans-Atlantic market when it pared its fourth-quarter operating margin forecast.

U.S. airlines have posted improved financial results this year after travel demand diminished in the economic downturn. Business travelers who are flying again, fees for baggage and higher fares have helped their bottom lines.

United Continental shares were down 0.2 percent to $24.25 in morning trading, and Delta was off 0.5 percent to $12.59. (Reporting by Karen Jacobs. Editing by Robert MacMillan)