Comment/Alan Dukes: When the hype indulged in by Ryanair and the Commission is stripped away, the outcome of their spat for air travellers is that Ryanair fares on existing routes into publicly owned airports will be a little less cheap.

A possible knock-on effect is that where, in the future, Ryanair finds another publicly owned airport to fly into, it will be unable to negotiate terms as advantageous as those it enjoyed in Charleroi. In addition, any advantageous terms offered to Ryanair by a publicly owned airport will have to be published and offered to other carriers.

This will increase competitive pressure on Ryanair, illustrating the well-known fact that competition is a two-way street.

It is most definitely not a world-shaking event. Nor is it a decision of "an evil empire", as the pouting Michael O'Leary claimed. Nor does it restrict competition: if anything, it will increase transparency in a small corner of the air passenger market, thereby promoting competition.

There could have been a bad outcome had saner counsels than those of EU Transport Commissioner Loyola De Palacio not prevailed. The evidence suggests she was about to wield a sledgehammer to crack a small nut (no, not Michael O'Leary, but the issue).

Other Commission members and, perhaps, our Minister for Transport, Mr Seamus Brennan, persuaded Ms De Palacio not to use this rather limited case as a basis for formulating general rules on what discounts, incentives or inducements airport authorities can use to encourage air carriers to open new routes to and from their airports.

Instead, what we got was the Commissioner's rather petulant decision to impose a mild sanction, largely because she had not been consulted.

She is reported to have said that, if the offending parts of the Ryanair-Charleroi deal had been notified to the Commission, a different decision might have been taken.

Apparently, EU transport ministers will discuss next month guidelines for the scope of deals airports can offer airlines. They should make haste slowly on this issue and refuse to be stampeded by Ms De Palacio and her advisers.

The first thing they should remember is that the EU already has detailed rules regarding state aids. It appears, indeed, that these rules provided the basis for the decision in the Ryanair-Charleroi case.

There is no evidence that I can see to suggest the state aid rules came up against a new problem in this case that they could not cope with. This suggests we do not need more rules.

The second thing they should remember is that not all airports are owned by public authorities and many of those that are so owned do not necessarily receive public money.

If they do not receive public money, then they cannot use it to distort competition in anybody's favour. If they are not using public money, then the state aid rules do not apply. If they engage in discriminatory treatment to the advantage of any one operator, competition rules apply.

Having remembered those two things, the ministers should bear in mind that the Commission is not an infallible judge of what conditions a prudent private investor would grant in order to attract business. This is the "private investor" principle, which the Commission apparently applied in this case.

Whether or not the Commission actually asked a private airport investor to give a view on this case is not recorded: somehow, I think not, although I am open to correction.

A part of the burden of Ms De Palacio's complaint was that the Charleroi aids to Ryanair were not notified to the Commission. Notwithstanding Mr O'Leary's justified claim that the deal was "the most publicised deal in the history of aviation" (he should know, since he himself probably gave it more publicity than anybody else), the Commissioner wins that point, and not just on a mere technicality.

The real question, however, is: was the deal open to other carriers? The airport authorities say the same offers were made to other carriers but they had not shown the same level of interest.

If that is the case, then the claim of discrimination against other carriers loses much of its force.

Ironically, if Mr O'Leary had been a little less talkative, other carriers might not have felt compelled to make such a fuss about the issue.

The Commission came to the conclusion that the Charleroi inducements involved state aid but that 75 per cent of the aid was permissible. In addition, however (and here is where there may be a problem for the future), the Commission has stated that admissible assistance should not account for more than 50 per cent of the cost of the service offered as aid, and that it should not be offered for a period of more than five years.

Reports suggest the Commission originally wanted to set a period of three years. There are plenty of precedents for a figure of 50 per cent aid (indeed, there are precedents for higher figures), but the period of five years appears rather arbitrary.

How long does it take to be sure that a competitive position has been established? Is this something like the old "infant industry" argument all over again? (Students of economic history will remember that infant industries never seem to grow up.)

This is where the ministers may be tempted to meddle. They should not.

At a time when the finance ministers of the current EU Presidency and its successors to the end of next year are starting a critical review of the regulation process, we should not rush to add even more regulatory rules to deal with an issue that has now been sensibly disposed of.

Alan Dukes is director general of the Institute of European Affairs