(Telecompaper) The UK Competition and Markets Authority (CMA) has written to the European Commission outlining its concerns about the proposed merger between Hutchison 3G UK and Telefonica UK (O2) and proposed remedies. CEO Alex Chisholm reiterated his agency's serious concerns regarding the proposed merger. The CMA believes that the merger would give rise to a significant impediment to effective competition in retail and wholesale mobile markets in the UK.