The chief executive of the parent group of Aer Lingus has said the possibility of flights being grounded at the end of next month when the UK is due to leave the European Union has been ruled out.

IAG CEO Willie Walsh said a framework had been negotiated and agreed at an EU level.

"The EU has been clear on this. Flights will continue. I remain confident that there will be a comprehensive air transport agreement between the EU and the UK."

"I can understand why people were expressing concerns a year ago, but there's been significant progress in the last 12 months. Everyone can be relaxed about what will happen in relation to aviation," he said.

IAG, which also lists British Airways and Spanish carrier Iberia among is brands, was de-listed from a number of global equity indices this week, precipitating a steep fall in the company's share price.

This, Willie Walsh said, had nothing to do with Brexit.

"This is a restriction that has been in place in our bylaws since we created the company. It relates to non-EU shareholders. It's similar to a lot of airlines. Wizz did something similar a year ago. Ryanair, I think, did it too. It relates specifically to airline ownership."

He said some had read into the decision as having to do with Brexit and reducing the level of non-EU shareholders in IAG. This, he said, was not the case.

"The timing of this relates to the increase in our non-EU shareholding. This was specifically US shareholders, but it has nothing to do with Brexit."

He wouldn't be drawn on what proportion of IAG shares are held by non-EU nationals as it was only made known to regulators.

"Given that we've introduced the max permitted, it suggest that non EU shareholders are less than 50% but probably more than 40%.

Willie Walsh was speaking as the airline reported higher profit and revenue for 2018.

Profit after tax and exceptional items came in at €2.9 billion, an increase of 11% on 2017.

Total group revenue of €24.4 billion was 6.7% higher.

Aer Lingus reported an operating profit of €305m for 2018, a 14% improvement on the previous year.