Currently this is mostly the case in Germany. The rail network is accesible for anybody and the subsidary running this has to give all companies the same rates

Currently this is mostly the case in Germany. The rail network is accesible for anybody and the subsidary running this has to give all companies the same rates and treatment, whether it is another subsidary of the same corporation or a different private rail company. For cargo this works quite well. There are many small companies doing transports. This goes from small companies which own one engine which you can hire to pull the cars you hire somewhere else over the network to large companies which work all over Europe. There is tough competition between those companies. For regional services this works in a way where local administrations call for bids to run specific lines. This works okay'ish and the government-owned company looses more and more of the services (one could argue whether that's good ...) Some of these biding processes fail miserably, like the current round for the commuter trains (S-Bahn) at Nuremberg which went through different court cases already. For long distance this is complicated as for long distance it is really hard to be profitable unless you are part of a bigger network. The national company operates long-distance without (direct) subventions (well, details of finances are complicated ...) thus there is little requirement to cooperate with private long distance companies. One typical example: Those Locomore tickets are only valid on their trains and there are no combination tickets from regional to locomore trains. The passenger not living close by a station where that private line goes has to get two independent tickets and has the risk that the second ticket is useless when the first train is late and he can't make the connection. Also train operation costs are high (you need an engine, cars and then the fees for the tracks) For a cargo train you can arrange with a customer to make sure you've got a full train etc. with a passenger train you need more than 50%, maybe even more, of the seats to be taken for being profitable this is extremely hard with a single connection ... and for multiple connections investment becomes very big.