United Airlines appears to have cancelled orders for a dozen Airbus A320-family jets, the airframer's latest backlog data shows.
While customers placed gross orders for 650 A320-family aircraft over the first six months of 2013, Airbus recorded cancellations for 12 in its June figures.
These comprised seven A319s and five A320s.
Airbus's backlog data for the month shows United Airlines' overall A319 order has reduced by seven, to 71, and its A320 order cut by five, to 112, since the end of May.
United had taken delivery of 55 A319s and 98 A320s, from its revised order of 183 aircraft, by 30 June.
Airbus secured net orders for 618 A320-family aircraft during the first half of the year including 358 A321s.
United's changes result in a net order deficit for the A319. Just one customer, a private operator, has ordered the A319 - a single airframe - over the period.