Air Transport World's annual global survey found that Ryanair's profit margins are significantly ahead of European rivals such as Easyjet, and have even eclipsed those of the original lowcost carrier, US airline Southwest.

Southwest, the airline that provided the blueprint for Ryanair's no-frills model, had operating profit of $820m ( 643m) and net profit of $548m ( 429m) last year. Over the same period Ryanair produced operating profit of 369m and net profit of 307m.

Southwest's performance was based on carrying 88.5 million passengers on its 453 aircraft. Over the same period, Ryanair carried less than half that number of passengers, 33.4 million, on just 107 aircraft. On a per airplane and per passenger basis, Ryanair emerged from the survey as far and away the most profitable airline.

On average, each Ryanair plane adds $3.45m to the company's bottom line each year compared to $1.2m for Southwest, the next best performer.

Each passenger produces $11 in profit for Ryanair versus $6.20 for the US carrier.

In European aviation, Ryanair's nearest challenger is Easyjet, which produced net profit of $0.67m per plane last year.

"I would say it's not a stretch to say it's the most profitable airline in the world, " said Goodbody Stockbrokers analyst Joe Gill. The key difference between Ryanair and Southwest, he said, was the Irish airline's success in boosting ancillary revenues such as in-flight food sales, baggage-handling charges and credit card booking fees.

The survey indicates that, while Ryanair may be 4m out of pocket as a result of the security measures adopted at British airports, it can well afford the hit.

Ryanair is currently seeking £3m ( 4.4m) in compensation from the British government in lost earnings from flight delays and cancellations as a result of the recent heightened security measures at UK airports.