Since the terrorist attacks in New York and Washington, the tourism and travel sectors worldwide have been thrown into turmoil. Airline companies in particular were already suffering from reduced demand and higher costs due to wage pressures and higher oil prices. Several years of operating on wafer-thin profit margins have left the balance sheets of US and European airlines in a parlous state.

There is a small number of listed companies on the Irish stock market that are heavily exposed to tourism and travel. The two largest are Ryanair and Jurys Doyle Hotel Group. Ryanair is by far the larger of the two, with a market capitalisation of €3.2 billion (£2.5 billion), compared with Jurys, which has a market capitalisation of €369 million.

Not surprisingly, the share prices of both companies have fallen sharply during the recent market meltdown. The table provides some key data for both companies and shows that Jurys' share price has fallen by more than 30 per cent since end-August, whilst Ryanair has fallen by a more modest 17 per cent.

These declines compare with a fall of 10 per cent for the overall ISEQ over the same period.

At a time when the fate of Aer Lingus hangs in the balance, it is noteworthy that Ryanair's share price has held up remarkably well.

This is despite the fact that the airline sector has been dealt a severe blow and many airline companies are now expected to go bankrupt or to be merged with rivals.

Ryanair's ability to swim against the tide would seem to be a function of the fact that its business model is totally different from that of the rest of the airline sector. Ryanair offers a no-frills service and is happy to operate out of secondary airports across Europe.

The company focuses on constantly reducing costs in a very proactive fashion. An example of the company's success in this regard is the speed with which it embraced the internet when it set up Ryanair.com.

Not alone has this enabled the company to reduce its costs dramatically but it has also generated extra revenues from sales of ancillary services such as car rental and travel insurance.

However, Ryanair's key ingredient for successful growth is that it uses its greater efficiencies to offer extremely cheap air fares.

This low-fares policy stimulates demand, thus enabling the company to grow at a very rapid pace. Investors have recognised the above-average long-term growth prospects, and the shares trade on a substantial price-earnings ratio (PER) premium to the market.

At a time when analysts are questioning earnings projections for many companies, confidence is still high that Ryanair can meet expectations of strong growth in revenues and profits.

In contrast to Ryanair's lofty PER of 27.0, Jurys Doyle Group's recent share price weakness means that it is now trading on a lowly PER of 7.1 and offers an above-average dividend yield of 3.5 per cent.

Unlike Ryanair, Jurys does not have a unique formula that sets it apart from its competitors. As the largest Irish hotel group it cannot avoid the negative impact of the foot-and-mouth crisis and the fall-off in the US travel market.

Nevertheless, it is a well-managed company and not totally dependent on the Irish economy, with 55 per cent of its profits now generated overseas.

The operating environment facing these two companies is likely to continue to be difficult for the foreseeable future.

Ryanair is very well placed within its sector but its relatively high share price would seem to reflect this. In contrast, Jurys Doyle Group cannot buck the weakness in the Irish tourism sector.

However, if Ryanair and other airlines succeed in opening new low-cost routes to Europe, at least some of the business lost from the US may be replaced. A prime beneficiary of this would be Jurys, which would benefit from such increased activity.

Despite the current highly uncertain economic and political climate, both of these companies are well managed and at their current share prices offer interesting investment opportunities.