The OECD Competition Committee debated portfolio effects in conglomerate mergers in October 2001. This document includes an executive summary and the documents from the meeting: an analytical note by Mr. Gary Hewitt for the OECD, written submissions from Australia, Canada, the European Commission, Finland, Germany, Hungary, Ireland, Japan, Korea, the Netherlands, Spain, Switzerland, the United Kingdom, the United States, as well as an aide-memoire of the discussion.