Yes, they always had a lot alliances...
The biggest and deepest was with Swissair. The shared nearly everything - from the computer systems to aircraft maintenance to simulators...
The were launch customers together for the DC-9-50, the MD
-80 and in recent times they bought together with Sabena the A330-200. They had a City Shuttle VIE
-ZHR which was operated jointly (one aircraft of each was equipped in the same way, the crews were mixed, departing VIE
it had an OS
-flight number, from ZRH
And all this started in the 80'is when the alliance boom of today was far away.
But all good things came to an end when Swissair wanted to buy a controlling interest in Austrian without telling them.... (they had already 10% and wanted to buy another 10 from All Nippon Airways)
But the Japanese were so friendly to tell it Austrian and so the deal did not materialize. You know the end of the story, Swissair is no longer but Austrian has found a new big uncle.... (LH