TUI is switching two Boeing 787-8 orders to the larger -9 variant and will acquire up to two additional -9s to satisfy increased demand.
The leisure group intends to take one new 787-9 per annum from September 2016 onwards, although it would need to convert an option to take the fourth in September 2019.
TUI will have taken delivery of its full complement of 787-8s – 13 aircraft – by September this year, says the group.
Group chief executive Friedrich Joussen says the 787-9s offer 45 additional seats which are required for "growing markets" in the Caribbean and Indian Ocean.
The third line has been amended for precision