A slight nitpick: BT was privatised in 1984 - what they did get was a strong regulator in the form of Oftel (now Ofcom) - it was Oftel who made BT offer Local Loop Unbundling (in general policy in 1999 and specifically as part of BT's license in 2000):

http://www.ofcom.org.uk/static/archive/oftel/publications/br...