THY is atleast 1-2 years away from a final decision regarding an alliance agreement. Exploratory discussions with the three alliances have taken place
However the way things are today, neither Star nor Oneworld would be the carriers primary choice. Skyteam might very well be the final choice.
Star's weakness is that Germany is THY's #1 international market, and the company sees Lufthansa as its #1 European competition. It is felt that regulators would object to an agreement that would lock up over 90% of the scheduled service seats between these two countries. In addition Star has some quite expensive IT
integration requirements, which run counter to some current THY projects and investments.
In the case of Oneworld, THY is currently having some difficulties with their American Airlines code-share agreement, particularly the sale of connecting inter-US flights. As a result THY has begun offering Delta flights beyond JFK
for connections. In addition Delta has approached THY regarding a comprehensive codeshare agreement covering both Trans-Atlantic services and US domestic flights. If this goes thru, I'd certainly say Oneworlds chances have become even weaker.
Lastly, THY does not want to feel like a junior member in an alliance. It will choose the alliance that provides the broadest revenue and market banefit to the carrier, its Istanbul regional hub, and Turkey as a whole.