The Republic's five largest public companies together created 13 per cent more wealth last year than in 2002, according to a new study from the UK's Department of Trade and Industry (DTI).

The research, which calculates the "value added" across the top 600 European companies, shows that the biggest Irish-listed firms generated wealth of some £7.5 billion (€11.5 billion) in 2003.

Four of the five - AIB, Bank of Ireland, CRH, Kerry Group - saw their value added rise substantially, with Elan the only top firm to add less value than in the previous year.

The wealth created by a company is measured as the value added. This is defined as sales less the cost of bought-in materials, components and services.

AIB created wealth of £2.1 billion last year, up 46 per cent on 2002 as the impact of a $691 million (€576 million) trading loss in the previous year washed out of the numbers.

Bank of Ireland's value added last year was £1.6 billion, up 6 per cent. Wealth created at CRH rose by just 2 per cent to £2.5 billion while Kerry Group created wealth of £690 million, up 17 per cent on 2002.

Elan, which concluded a radical restructuring in 2003, saw the level of wealth it created drop by 8 per cent to £586 million.

The survey also includes an analysis of Eircom and Jefferson Smurfit, neither of which were listed in 2003. Eircom's value added dropped by 24 per cent to £596 million last year. Value added at Smurfit declined by 5 per cent to £1.2 billion.

The overall value added for the top 600 European companies in 2003 was £1,326 billion, up 1 per cent on the previous year.

The 165 UK companies in the European 600 increased their total value added by 5 per cent over the same period, accounting for £325 billion of value added.

As well as the survey of the top 600 European companies, the DTI also looked at the top 800 UK companies. The survey said that wealth creation amongst UK companies was ahead of the European average. Since last year, value added by the top 800 UK companies has increased by 4 per cent compared with the 1 per cent increase by the European top 600. Royal/Dutch Shell, BP and Vodafone were the leading UK firms, the survey said.

There are more UK companies in the European 600 than any other country. Second is Germany with 89 companies followed by France with 83.

The German firms increased their value added by 1 per cent while the French companies' value added fell by 1 per cent.