The Irish Maritime Development Office (IMDO) is to press the Minister for Finance, Mr McCreevy, to introduce a new tonnage tax system for shipping in his next budget, due to be unveiled in December.

The Minister rejected a similar proposal from the IMDO last year, but observers believe that a refined submission will have a greater chance of success this year.

The European Commission has been a proponent of tonnage tax for a number of years.

The proposed system, supported by the Minister for the Marine and Natural Resources as well as by various shipping industry groups, would allow shipping companies to be taxed on profits calculated by referring to the tonnage size of a fleet as opposed to actual profits or gains from the trade, as is the norm for corporation tax purposes.

One of the advantages of tonnage tax is that the taxable profits can be predicted (given that the tonnage of a ship does not change) so a tonnage tax company can budget for its tax liabilities with a large degree of certainty.

This is seen as an attractive option for many shipping companies, including Irish Continental.

According to an IMDO spokesman, a tonnage tax system is "almost imperative" if the Republic's shipping register is to be maintained at anything approaching healthy levels.

The Irish fleet has been dwindling in recent years and now numbers less than 50 seaworthy vessels.

The spokesman said that the transparency of a tonnage regime would help to preserve that fleet, and may even help to attract additional registrations from non-EU countries.

Ancillary shipping services would also be boosted, he explained.

Nine out of the 15 EU member states currently have tonnage regimes in place.