Brazil tried it, we had a state company that had a monopoly of telecom, we broke it up intentionally in many tiny parts and sold them.
Results were basically this:
1. A bunch ended eventually merging, often with help of blatant corruption (for example one such merger was first denied, then approved again after the son of the president "sold" to a telecom company, his game company for 30 million, a game company that never made any games, and the son of the president before that was a zoo caretaker and didn't knew how to code).
2. Some are going bankrupt, with parts they bought being unprofitable, and will eventually get merged into the others.
3. A LOT of international 007-style spy shit happened because of this... We had our version of CIA spying on our own president, owner of a bank spied upon (seemly with good reason), Italy and Brazil spying on each other, agents getting arrested, agents disappearing, people bending backwards to release criminals and suspected criminals to avoid diplomatic incidents, people that disappeared or died, etc...
To be honest Telecom looks like the sort of thing that even touching with a mile-long pole you will still get shit splattered on you, and if you try a shorter pole it will be nuclear shit.