Kolmården Zoo in Sweden was started by the city of Norrköping in 1965. Not so long ago, though I am not sure exactly which year, it was sold to a private company that owns the big amusement parks in Sweden. There has been a bit of "amusement" added to the park since then but as far as I know of animal welfare has not been compromised.
One of my two "home zoos" has just been totally privatisised: Skanes Animal Park (see The Gallery). It has always (I believe) been owned by a foundation but also been publicly supported. It will now receive a final payment from tax payer´s money, the equivilent of about 1,5 US dollars (not exactly a fortune...), and will then try to make it on its own. I am not totally positive about its future. It is essentially a wildlife park with Nordic animals, situated just outside a very small city in the south of Sweden. Annual visitors about 200 000, if I remember correctly.