EADTU is the European Association of Distance Teaching Universities. It styles itself the "representative organisation of both the European open and distance learning universities and of the national consortia of higher education institutions active in the field of distance education and e-learning". In UK relevance, the members are the Open University and the Open Learning Foundation.
For more details see the EADTU web site.
EADTU have under development a benchmarking and quality assurance/enhancement methodology called E-xcellence.
The Open Learning Foundation contains over 20 UK universities including several active in either the pilot or in Phase 1 benchmarking.
English members include Anglia Ruskin, Brunel, De Montfort, Derby, East London, Lincoln, Liverpool, Northumbria, Salford, Sheffield Hallam, Teesside and Thames Valley
Scottish members include Napier, Paisley and Robert Gordon.
Welsh members include the University of Glamorgan, University of Wales, Bangor and University of Wales College of Medicine
There are also some specialist and private institutions as members including Cambridge Management Institute and Ultralab.
A full list of members is available.