Estonian Air is owned 51% by the Estonian state and 49% by Danish Maersk Air. Operation is tightly integrated with Maersk, and they operate the same aircraft types, F-50 and B737-500. Half of their planes are simply rented from Maersk. When an Estonian plane is missing due to maintenance, then a Maersk plane is automatically substituted.
Maersk Air "married" more or less with SAS a couple of years back, and one consequence of that marriage was that SAS and Estonian began code sharing with SAS same way as Maersk.
Air Baltic in neighbour country Latvia is much the same, but there it is SAS having the minority stake in the company.
Best regards, Preben Norholm
Always keep your number of landings equal to your number of take-offs