Action by Britain's market regulators has international ramifications; the CMA's interventions in the Arm-Nvidia deal were partly responsible for the cancellation of the $66 billion sale of the British chip designer to Nvidia. And it has held up Facebook's purchase of Giphy.
As for the antivirus vendor pact, the $8.6 billion merger was announced in August 2021 and, after a gentle probe, the Competition and Markets Authority (CMA) decided that a closer look was needed in March 2022. That closer look (referred to as a Phase 2 investigation) is pretty much done and dusted and the CMA has provisionally decided that the deal doesn't raise competition concerns in the UK.
This is due to existing players, including the duo's main rival in the UK, McAfee, and Microsoft's bundling of its own security applications into Windows.
So: Bullguard got taken over by Norton (LifeLock). AVG got taken over by Avast. Now Norton & Avast are merging! Not sure this is a good thing... Want to see which security vendor is best? Check with AV-Test, or contact Donline.