There are several synonyms for the term "aforementioned merger" that you can use to avoid repetition while still conveying the same meaning. One possible alternative is "a previously noted amalgamation," which emphasizes that the merger has already been discussed or mentioned before. Another option might be "a recently mentioned integration," which implies that the merger has only been brought up recently or is still in the process of being finalized. You could also use "a previously referenced consolidation," "a previously stated unification," or "a prior merger that was mentioned," depending on the context and purpose of your writing. Whatever synonym you choose, be sure to use it consistently throughout your text to avoid confusion.