According to the Financial Times, the EU had already said in February that it had received several complaints about the deal and would need to have a think about it. It did have concerns that it might significantly affect competition in the market for interactive product design and whiteboarding software.

Now, the Brussels-based Commission has decided that it open a phase II investigation which takes more time and goes deeper. A phase II investigation "typically involves more extensive information gathering, including companies' internal documents, extensive economic data, more detailed questionnaires to market participants, site visits, more reports which must be burnt and recycled as firelighters.

From the start of such a probe, the regulatory body has 90 days to make a decision.

The EU is not the only one interested the US Department of Justice and the United Kingdom's Competition and Markets Authority are looking into the digital design tool deal. The DOJ is reportedly preparing to file an antitrust suit blocking the merger, while the UK CMA is actively investigating the acquisition, with a first decision due by the end of June.