Air Berlin has converted orders for 15 Boeing 787-8s to the stretched and longer-range 787-9 variant.
Etihad Airways chief executive James Hogan, whose company owns a 29.21% shareholding in the German low-cost carrier, confirms that the order conversion was recently finalised with Boeing.
The conversion increases the list value of the six-year-old Air Berlin deal by 17.9% to $3.65 billion. Air Berlin also has options to buy five more 787s, according to the Flightglobal Ascend database.
The move also aligns Air Berlin's 787 order with Etihad's backlog that includes 41 787-9s. The two carriers have already taken steps to package there separate orders for the new Boeing widebody. Air Berlin last year selected the General Electric GEnx-1B turbofans, matching Etihad's choice. They are also combining purchases of avionics, cabin specifications and rotables.
It was not immediately clear how the change could affect Air Berlin's delivery schedule. The carrier was due to receive the first 787-8 in about 12 months, the Flightglobal Ascend database shows.
Boeing plans to start flying the 787-9 later this year, with certification expected by the end of 2013.
Air Berlin CEO Wolfgang Prock-Schauer reportedly told German reporters in early March that he was considering a change to the 787-9. The larger variant carries up to 40 more passengers than the 787-8. The 787-9 can also reach cities up to 8,500nm (15,750km) away, or about 300nm farther than the maximum listed range of the smaller variant.