The Taoiseach, Mr Ahern and the Minister for Foreign Affairs, Mr Andrews, praised the SDLP's role in the peace process in messages read to conference delegates.
The leader of the Socialist group in the European Parliament, Mr Enrique Baron Crespo and Labour MP Mr Kevin McNamara were among several fraternal delegates at the conference.
Other guests included Fianna Fail TD Dr Rory O'Hanlon and Fine Gael TDs Mr Charles Flanagan and Mr Austin Currie. Also present were the American consul general in Belfast, Ms Jane KiFort, the head of the European Commission office in Belfast, Mr Jim Dougall and the chief commissioner in the North's Equality Commission, Ms Joan Harbison.