A system (10) for sorting search results according to a buyer profile (47) during the matching phase of an electronic commerce transaction includes a database containing a buyer profile (47) associated with a buyer (20), the buyer profile (47) comprising a record of the number of times each of multiple sort criteria has appeared in at least some previous events involving the buyer (20). A server (40) receives multiple search results communicated from one or more seller databases (32) in response to an under-constrained search query in which exact attribute values are not specified for one or more attributes. The server (40) accesses the buyer profile (47) to determine an order of display based on the number of times one or more sort criteria in the buyer profile (47) applicable to the search results have appeared in the previous events involving the buyer (20). The server (40) sorts the search results according to the determined order of display and communicates the sorted search results to the buyer (20).