Aer Lingus owner International Airlines Group (IAG) has warned that strikes in France are posing a challenge to its operations.
The airline group, which owns British Airways, Vueling and Iberia, said strikes were causing disruption for customers and hurting the Spanish economy.
The firm has joined forces with other carriers to complain about the strikes to the EU.
Willie Walsh, IAG's chief executive, said: "Unfortunately, French air traffic control strikes continued to challenge our airlines' operations, causing disruption to our customers.
"Vueling was particularly affected and incurred an additional €20m of disruption costs in the quarter.
"These strikes are also having a significant impact on the Spanish economy and tourism."
In the six months to June 30, operating profit, before accounting for exceptional items, was up 17.4% to €1.12bn at IAG.
Total revenue rose 3.1% to €11.2bn.
Aer Lingus CEO, Stephen Kavanagh said: “Aer Lingus has an ambitious flight path – to be the leading value carrier across the North Atlantic. This vision is enabled by a profitable, sustainable short-haul network; and is supported by a guest-focused brand and digitally-enabled value proposition.
"Todays’ results are the latest manifestation of the airline’s successful business model," he said.
Liberum analysts said IAG was one of the few airlines that would achieve profit growth this year.
"Although the trading environment may not be as supportive as last year, with toughening unit revenue comparatives and rising fuel prices, we see IAG as the best positioned of the network carriers to deal with these potential challenges," they said.
IAG's figures come after Mr Walsh co-ordinated legal action with easyJet, Ryanair and Wizz Air to complain to the European Commission about strikes in France.
The airlines have claimed that France's strikes breach the "fundamental principle of freedom of movement within the EU", having already caused tens of thousands of flights to be cancelled this year, impacting millions of passengers.
They alleged that France is breaking EU law by not enabling flights over the country during strikes, denying passengers their fundamental freedom to travel between member states not affected by strike action.
The news comes as 100 Irish-based Ryanair pilots are picketing the airline’s HQ in Dublin for a fourth day today in a dispute over working conditions.
More than 20 flights have been cancelled, disrupting the travel plans of 3,500 passengers.
Ryanair claims the strike is being driven by a tiny handful of Aer Lingus pilots who are working with other unions across Europe to coordinate widespread disruption, something pilots union FORSA denies.
A fifth day of action is planned for next Friday, the same day as strikes by other Ryanair pilots in Belgium and Sweden.
The airline has described the move as irresponsible, unwarranted and damaging.
PA & Digital Desk