Ryanair confirmed it is in talks with one of the airports it has insisted it would never use - Charles de Gaulle in Paris - as the success of its customer-focused strategy helped boost its full-year profits by 66pc to €867m last year.
The figure was a record for Ryanair, which launched 30 years ago this July.
Shares in the airline soared over 7pc at one stage yesterday to €11.70 as it predicted that profits in the current financial year will jump as much as 10pc to between €940m and €970m. Davy Stockbrokers raised its price target for the stock to €12.
Ryanair's chief commercial officer, David O'Brien, insisted that Heathrow is of "no interest", even if IAG were forced by competition tsars to offload some take-off and landing slots if it succeeds in buying Aer Lingus.
Ryanair executives have previously said there are three airports in Europe that the airline won't use because costs there are too high, and because congestion makes it too difficult to achieve its set-in-stone 25-minute aircraft turnaround.
Those airports are Heathrow, Charles de Gaulle and Frankfurt. But it has also indicted that if the right prices were available, it would consider Charles de Gaulle, for instance.
"We have been talking to Charles de Gaulle," said Mr O'Brien. "There is no u-turn that we won't execute. It's an expensive place, it's a complicated place. We talk to all airports."
He claimed that one in three of all new European short-haul passengers in years to come will be Ryanair passengers and that increased the incentive for airports all over Europe to attract the airline's services.
But he said Heathrow will remain out of bounds for Ryanair.
"Heathrow is a very expensive, complicated airport with limited slots," said Mr O'Brien.
"We have a tremendous airport in Stansted which has more than enough capacity for the moment. Heathrow, quite frankly, is fantastically overrated."
The expansion into primary airports has also put pressure on Aer Lingus short-haul routes.
Ryanair, whose chief executive is Michael O'Leary, has spent nearly the last two years overhauling its service to customers, introducing a range of passenger-friendly initiatives, as well as luring families and business travellers.
It is also targeting growth at primary airports in Europe, putting it in even more direct competition with rivals from Aer Lingus to Lufthansa and EasyJet.
Ryanair is rolling out a range of additional revamps this year, including new cabin crew uniforms, new aircraft interiors, a new onboard menu and a new website. It's also trialling initiatives such as wi-fi and in-flight entertainment services.
Revenue at the airline, which has a fleet of 320 aircraft, rose 12pc last year to €5.65bn, while it carried 90.6 million passengers in the 12 months to the end of March. Its load factor, or percentage of available seats it filled on its aircraft, was 90pc during the last financial year. It is predicting that it will carry 100 million passengers in the current financial year.
The carrier also said that its forward bookings for the upcoming summer season are running about 4pc ahead of summer last year.
Ryanair warned that competitors, especially those that don't hedge their fuel costs, could succumb to "irrational pricing" in coming months.
That could put pressure on its own yields.