Ottawa-based premise and cloud-based unified communications solutions provider Mitel Networks Corp. announced that it plans to acquire Texas-based Mavenir Systems for about US$560 million. The acquisition will be funded with a mix of debt and equity. We believe the transaction has the potential to significantly enhance Mitel?s growth profile in the medium term, but carries risks. As a result, we are revising our outlook on Mitel to stable from positive. At the same time, we are affirming our 'B+' long-term corporate credit rating on the company. Our recovery and issue-level ratings on Mitel's existing debt are unchanged and we plan to assign ratings to the proposed new debt, which will replace the existing debt, once we receive additional details. We