[calgarymicro]

Because they both operate in the EU, have customers in the EU, make money in the EU, and have legal presences in the EU. Generally, any merger of large multinational corporations will require multinational approval - the US and EU at a bare minimum, often also the UK, Japan, China, and any other countries with strong regulatory regimes where one of the companies has a major/critical presence.

Any one of these countries can block a merger if they see an antitrust issue; Qualcomm and NXP found this out the hard way with China a few years ago, and Microsoft and Activision Blizzard are finding that out with the UK right now. Of course, these companies could flip off China or the UK and just merge anyway, but then they'd risk being subject to crippling fines, having their local assets seized, and even being barred from doing business in that market altogether.