Etihad Airways (EY, Abu Dhabi International) is set for another round of dealings with Germany's federal aviation office (Luftfahrt-Bundesamt - LBA), just weeks after its Air Berlin (1991) (Berlin Tegel) subsidiary successfully overturned an LBA ruling which would have blocked the two carriers from codesharing on 34 flights this winter.

According to Germany's aero.de magazine, the LBA has announced it is close to finalizing a detailed investigation into Air Berlin's ownership and shareholding, in which Etihad has a 29.21% stake.

As with a similar European Commission inquest, the regulatory body wants to determine the extent to which Etihad has a say in Air Berlin's operations. Though Air Berlin is majority owned by German investors to the tune of 55.34%, European law states that overall control of any European carrier's operations must rest in the hands of its nationals.

Questions over the Emirati carrier's say in its European portfolio of carriers have been raised given the size of financial loans and the investments extended to them - Air Berlin in particular.

In June, Etihad announced it would assist Air Berlin with over EUR300million in funding to help in its restructuring programme aimed at returning the carrier to profitability by 2017.

Having nixed a USD5billion order with Boeing (BOE, Washington National) for fifteen B787-9s and eighteen B737-800s in September, Air Berlin is also set to streamline its narrowbody fleet with the addition of fourteen A320-200s, formerly with fellow Etihad-affiliate, Alitalia (AZA, Rome Fiumicino). The German carrier's narrow body needs are currently also supplied by TUI fly (Germany) (X3, Hannover) and its fleet of five B737-700s and nine B737-800s, under a wet-lease agreement set to run until 2019. Austrian Aviation Net claims Air Berlin is currently in talks with TUI over compensation claims for a likely early termination of the contract.