I don’t really know, I’m sure it’s in the local paper archives. I lived in South Yorkshire at the time and the joint councils also decided to do a similar thing, and while fares increased (from 10p for adults and 2p for children for most journeys) it still seemed the right thing to do. In comparison Leeds sold off the transport department on day one and the consequences of that are still being seen. Arguably Nottingham allowing a bit of transport business investment may have fended off Stagecoach and First from forming monopolies like they have in many places.
There were large bus businesses before Stagecoach and First (BET and Tilling for example) but I think deregulation was ideological first and at best the emergence of local and regional monopolies was the invisible hand of the markets.