A 'Celtic Cup' involving the Republic of Ireland, Northern Ireland, Scotland and Wales moved a step closer to reality tonight after all four national associations agreed "in principle" to a biennial tournament starting in 2009.

The agreement was announced on the Football Association of Ireland's website and commits the countries to arranging three tournaments, played on a league basis.

Home and away games will be rotated from one tournament to the next, in the manner of rugby union's Six Nations, with each team playing three matches per tournament.

Commercial arrangements and fixture dates are now being finalised.

The statement was signed by FAI chief executive John Delaney, his IFA counterpart Howard Wells, Scottish Football Association chief executive Gordon Smith and Football Association of Wales general secretary David Collins.