EU Deal Probes at Risk as Court Aide Faults Illumina Case (2)

The European Union’s deal watchdogs suffered a blow after an aide to the bloc’s top court said they exceeded their authority by probing Illumina Inc.’s now abandoned $7 billion acquisition of cancer-test provider Grail Inc.

The European Commission’s decision to test out a new deals-vetting procedure — known as Article 22 — in the Illumina case risks “a very significant extension of the scope” of the merger rules, Advocate General Nicholas Emiliou of the EU’s Court of Justice, said in a non-binding opinion.

“In one fell swoop, the commission would gain the power to review almost any concentration, ...