Etihad Airways (EY, Abu Dhabi International) and its stakes in several European airlines including Air Berlin (1991) (Berlin Tegel), Aer Lingus (EI, Dublin International), Darwin Airline (Lugano), and Air Serbia (JU, Belgrade) have come under the European Commission's scrutiny following the Emirati carrier's recent shopping spree. Delta Air Lines (DL, Atlanta Hartsfield Jackson) and its 49% shareholding in Virgin Atlantic (VS, London Heathrow) will also be investigated.

The bureaucracy said its commissioners doubt Etihad's and Delta's investments are in line with European Union laws regarding ownership and effective control. Swiss regulator, the Federal Office of Civil Aviation (FOCA), said it would launch its own investigation into Etihad's stake in Darwin Airline.

European law requires an airline pass two separate tests of ownership and control in order for it to retain its "European" designation and associated privileges.

“We are tightening the screw, if you like,” DG-Mobility and Transport Matthias Ruete told AirTransportWorld. “We have clear rules on ownership and control of EU airlines and they must be adhered to. And while the ownership issue is straightforward, the control issue is a difficult one because what that actually means is open to interpretation. There have been some cases over the last few years where we have had to warn states that they were moving into a realm of activity not possible under EU law.”

The European Commission has also warned Italy that any restructuring of Alitalia (AZA, Rome Fiumicino) in the wake of a possible deal with Etihad would be subject to the same laws and regulations.