The ... World ... Convention in Beijing has been a tremendous success, for which your participation as one of our guest speakers has undoubtedly been of paramount importance.
I would like to seize the opportunity to thank you on behalf of ... for your excellent contribution to the Intercultural Workshop, and I hope that this experience has been as enjoyable for you as it has been for us.
I very much look forward to future opportunities of co-operation.
(International federation/ offices in 65 countries)