International Airlines Group saw August passenger numbers jump by more than 12% to 9.1 million.
The parent company of British Airways, Iberia and Spanish low-cost carrier Vueling recorded an 8.7% increase in premium traffic for the month compared to August 2014.
Group traffic in August, measured in revenue passenger kilometres, increased by 8.6% year-on-year, outstripping increased capacity of 6.1%.
All regions saw a rise in passenger carryings with the exception of North American routes, which dropped by 0.7% as capacity was trimmed by 2.1%.
Europe recorded an 18.7% rise in carryings to 4.8 million, followed by Latin America and the Caribbean, up by 17.7% 425,000.
The IAG figures follow strong August numbers delivered by Ryanair, easyJet and Wizz Air this week.
IAG-owned Aer Lingus saw August passenger numbers rise by 5.3% to 1.27 million. Long-haul carryings were up by 16.9% to 173,000 and short-haul by 5.7% to 965,000.
But numbers flown by the Irish carrier’s regional arm dropped by 9% to 131,000. Overall carryings for the year to August edged up by 0.9% to 7.7 million.