The EU General Court has upheld the European Commission's decision to prohibit Booking Holdings' proposed acquisition of eTraveli, the Swedish flight booking software group. The ruling confirms one of the most consequential merger prohibitions issued by the Commission in recent years and leaves the online travel reservation sector with its existing competitive structure intact.

The case concerns the Commission's decision of September 2023, in which the EU merger authority blocked Booking.com's approximately €1.6 billion acquisition of eTraveli. The Commission reasoned that the transaction would have strengthened Booking's dominant position in the European market for online travel agency services for hotel bookings. Booking, already the largest online travel platform in Europe, would have gained control of a flight booking business that the regulator viewed as a potential avenue for new competition and a complement capable of reinforcing Booking's hotel dominance through bundle effects.

Booking Holdings challenged the prohibition before the General Court, one of the two courts of first instance of the Court of Justice of the European Union, arguing that the Commission had overreached in its assessment of the deal's effects. The company contended that the transaction concerned adjacent rather than overlapping markets and that the Commission's theory of harm was too speculative to support a prohibition.

The General Court rejected those arguments. In its judgment, the Court found that the Commission had not erred in its competitive assessment and that the prohibition stood on solid analytical ground. The judgment represents a significant endorsement of the Commission's willingness to deploy its merger control powers against so-called ecosystem or portfolio effects — theories of harm based not on horizontal overlaps but on the risk that a dominant platform could leverage its strength across adjacent services to foreclose rivals.

For practitioners, the practical consequences are considerable. The judgment confirms that the Commission may block acquisitions by dominant digital platforms even where the target operates in a neighbouring market, and that conglomerate and portfolio theories of harm remain viable bases for prohibition under the EU Merger Regulation. Deal teams advising technology and platform businesses will need to weigh these risks carefully when structuring acquisitions of complementary assets in Europe. The ruling also reduces the prospects for similar transactions by dominant platforms seeking to expand into adjacent verticals without meaningful remedies. Booking retains the option of appealing the judgment on points of law to the Court of Justice, but the prohibition now stands as the operative position under EU competition law.

The decision reinforces the Commission's broader enforcement posture toward large digital platforms, a stance that has shaped European merger control throughout recent years. Companies contemplating cross-border acquisitions in the digital economy will need to treat the Booking/eTraveli precedent as a central reference point in their antitrust risk assessments.