Part 1 of this paper describes the background to a pilot project conducted at a number of companies by Achmea Holding in The Netherlands. The aim of the study was to set up knowledge networks between circles of interest using a common infrastructure. Parts 2 and 3 respectively present and evaluate the results of the study. The pilot study results were meant to be used for introducing knowledge networks on a European scale and creating synergy between knowledge workers at Eureko an alliance of leading national insurance groups. The evaluation made use of GDSS (Group Decision Support System).