Chief executive Willie Walsh highlighted “adverse currency impact” following June’s referendum vote as the reason for the profits hit.
Despite the shortfall, IAG, whose carriers include Aer Lingus, Iberia and Vueling, saw operating profits rise by 8.6% to €2.5 billion in spite of a 1.3% decline in revenue to €22.5 billion.
The Group said it expected operating profit for 2017 “to show an improvement” based on current fuel prices and exchange rates.
In total, Group airlines carried more than 100 million passengers – an increase of 12 million from 2015 - with passenger load factor seeing improvement across three out of its four carriers.