The growth in economy travel outstripped premium traffic levels in May at British Airways/Iberia parent International Airlines Group.
IAG saw 7.5% growth in non-premium traffic and 1.7% in business and first class travel over the same month last year.
Overall traffic measured in revenue passenger kilometres was up by 3.8% on a like for like basis, while capacity grew by 2.5%.
“Trends for June appear stronger than those in May.” IAG said.
“Underlying market conditions at our London Heathrow hub continue to be firm, particularly in long haul premium.
“However, commercial performance at our Madrid hub has deteriorated further due to the ongoing effects of the Spanish and wider eurozone macroeconomic conditions and, the after-effects of prolonged industrial action.”