The Lufthansa board of directors is delaying a decision on who will replace CEO Christoph Franz until early next year.

The board had initially considered making a decision at its Dec. 4 meeting, but Chairman Wolfgang Mayrhuber now says more time is required. Carsten Spohr, CEO of the passenger airline unit, is seen as the most likely successor, industry observers tell Aviation Week.

Franz is leaving the German airline in April to join Swiss pharmaceutical group Roche. Rather than just giving the job to Spohr, Lufthansa initiated a search including internal and external candidates, and this process started in earnest a few weeks ago.

That approach has been contentious. Lufthansa has limited the external search to executives with airline experience; any candidate would also have to be fluent in German, observers note. That is narrowing down the number of contenders to a very small group, including Aer Lingus CEO Christoph Mueller, and none of these possible candidates are viewed as an obvious choice or a better option than Spohr.

But insiders say that Mayrhuber wants to make absolutely sure that a formally correct process can be documented. Following strong criticism from institutional investors, he was elected to his position earlier this year with only a small majority of shareholders.

The delay means the leadership question will likely remain unresolved until early March, unless the board is called for an extraordinary meeting before then.

If Spohr is named CEO, several candidates could replace him at the top of the airline operation. One executive who is mentioned internally is Karl-Ulrich Garnadt, currently the CEO of Lufthansa Cargo. Garnadt has also been the head of network planning, among other positions at the carrier. Another possibility is Thomas Kluhr, a member of the passenger airline division’s executive board in charge of the Munich hub and finance.

A third candidate being mentioned is Swiss International Air Lines CEO Harry Hohmeister, who is also a member of the group executive board with responsibilities for all airline affiliates.