Air Berlin has singled out Recaro as seat supplier for its narrowbody fleet.
All of the airline's Airbus A320 and Boeing 737 aircraft will be exclusively equipped with the German manufacturer's BL3510 economy class seat by the end of 2014.
The majority of this fleet is already equipped with the model, though some aircraft are still fitted with other manufacturers' seats.
Air Berlin and Recaro have now inked a long-term partnership to upgrade the seats, the airline says.
Last year, the carrier selected Germany-based Zim Flugsitz to supply 'Eco01' long-haul economy class seat for its 12-strong A330-200 fleet.