BRUSSELS (Reuters) - The chief executive of British Airways-owner IAG (>> International Consolidated Airlines Group) is confident a deal will be done to secure Britain's flying rights after Brexit, he said on Tuesday, dismissing a recent media report and a rival airline's prediction of disruption.

IAG's Willie Walsh told the Airlines For Europe conference that he expects Britain to secure deals to allow planes to keep flying and that he is relaxed about Brexit.

"I am a firm believer that this will get resolved," Walsh said on a panel.

He dismissed a report in Britain's Financial Times newspaper on Tuesday that said the United States had offered Britain a worse deal than it has under the EU-U.S. Open Skies agreement.

"The people who are involved in the negotiations say we're going to get a deal," Walsh said.

"There will be a comprehensive Open Skies agreement. Anyone who doesn't believe that is living in cloud cuckoo land."

Ryanair's (>> Ryanair Holdings plc) chief executive was less optimistic, however, saying he expects disruption to flights between Britain and the rest of Europe in the immediate aftermath of Britain's planned exit from the European Union on March 29 next year.

"I think there will be a real crisis in April 2019. I believe there will be disruption to flights between the UK and Europe," Michael O'Leary told the conference.

After Brexit, British airlines want to be able to continue to benefit from EU flying rights and the British government has said it will try to secure an open-access deal.

Flying rights to, from and within the European Union, as well as between the United States and Britain, are currently covered by EU-wide Open Skies agreements.

Britain needs to agree new deals because, without membership of the EU, the country's aviation sector does not have a natural fallback arrangement that will keep airlines flying.

Lufthansa CEO Carsten Spohr said on the sidelines of the conference that he expected a longer transition period would be needed because of complexities of the overall Brexit process.

(Reporting by Sarah Young and Victoria Bryan; Editing by David Goodman)