The things is that the telephone network itself is still essentially owned by the government and multiple companies compete to provide service. And fiber is to large extent operated under a similar model. (950 000 of the 1 300 000 are municipal broadband).
The cable monopoly, including exclusivity contracts, was instead sold to EQT (which later sold to someone else) and of course instead of opening up to competition they kept the monopoly in place.
It isn't that EQT was doing something awful (their schools with inflated grades are probably worse in that regard). Internet connectivity in Sweden is still rather good. It is just that PE firms generally do whatever makes them money, not necessarily what is good for consumers or anyone else.
[0] In Swedish, page 106: http://www.konkurrensverket.se/globalassets/publikationer/ra...