If by their own you mean one of numerous other cable companies that they purchased then yes. There used to be a plethora of small cable companies in the UK. Now there is only Virgin.

The widespread availability of high quality ADSL does seem to do a good job of keeping them honest though. I've been a pretty satisfied customer of them for many years now.

Virgin offer a "cable" service which is available where they have cable television (not a wide distribution area), and that this is what they refer to as their fibre service.

Virgin also resell the same ADSL that everyone else does (complete with BT line rental).