The
electricity market in the UK was built upon the break-up of the CEGB into four companies in the 1990s. Its generation (or upstream) activities were transferred to three generating companies, 'PowerGen', '
National Power', and '
Nuclear Electric' (later 'British Energy', eventually 'EDF Energy'); and its transmission (or downstream) activities to the '
National Grid Company'. The shares in National Grid were distributed to the
regional electricity companies prior to their own privatisation in 1990. PowerGen and National Power were privatised in 1991, with 60% stakes in each company sold to investors, the remaining 40% being held by the
UK government. The privatisation process was initially delayed as it was concluded that the 'earlier decided nuclear power plant assets in National Power' would not be included in the private National Power. A new company was formed, Nuclear Electric, which would eventually own and operate the nuclear power assets, and the
nuclear power stations were held in public ownership for a number of years. In 1995, the government sold its 40% stakes, and the assets of Nuclear Electric and
Scottish Nuclear were both combined and split. The combination process merged operations of
UK's eight most advanced nuclear plants – seven
advanced gas-cooled reactor(AGR) and one pressurised water reactor (PWR) – into a new private company founded in 1996, '
British Energy' (now '
EDF Energy'). The splitting process created a separate company in 1996 called '
Magnox Electric' to hold the older
Magnox reactors, later combined with
BNFL. Although electricity privatisation began in 1990, the CEGB continued to exist until the '''''' (
SI 2001/3421), a
statutory instrument, came into force on 9 November 2001. Powergen is now
E.ON UK, owned by the German utility company E.ON, who then further split to form Uniper, who own the majority of the former E.On conventional power generation. National Power split into a UK business, 'Innogy', now 'RWE npower', owned by the German utility company
RWE, and an international business, 'International Power', now
Engie Energy International and owned by the French company
Engie. ==Arms==