NEW YORK UAL Corp's United Airlines said on Monday it is doubling the fee to check a second bag on a domestic flight from $25 to $50 one-way.
United estimated the fee will apply to only one out of seven customers.
The fee will not apply to customers in the United First or United Business programs, those with Premier status with United or Star Alliance, or active duty military personnel traveling on orders.
United said the potential revenue from its merchandising efforts, including checked bag fees, will be $700 million in 2009.
On June 12, United introduced a $15 fee to check a single bag. Amid high fuel prices and a slowing U.S. economy, airlines have been introducing fees, raising fares, and cutting routes, capacity and jobs in order to survive.
(Reporting by Mark McSherry, editing by Gerald E. McCormick)