UAL Corp.'s United Airlines on Friday raised round-trip fares by $10 on most domestic routes to offset rising fuel costs.

The increase by Chicago-based United affects more than 16,000 routes in the U.S. for both leisure and business travelers, said Rick Seaney, chief executive officer of price-tracking Web site, in an e-mail.

Last month, several U.S. carriers increased their domestic fuel surcharges to a record $40 round trip.