EDF Energy has reached an agreement with China General Nuclear Power Corporation (CGN) for a nuclear power plant at Hinkley Point, Somerset coast.

It was confirmed yesterday at a news conference by Prime Minister David Cameron and Chinese President Xi Jinping, who is in the middle of a four-day visit in England.

The mainly state-owned EDF said the final cost would be £18bn (€24.5bn). State-owned CGN will pay £6bn (€8.2bn) for one third of it (33.5% stake).

The companies also announced preliminary agreements to work together on two more nuclear power stations: Sizewell C in Suffolk and Bradwell in Essex. The latter has attracted particular criticism because it will give primary ownership of the project to CGN – and use Chinese technology.

While they have reached Strategic Investment Agreements for all three plants, only Hinkley has a target date. The plant was originally scheduled to open in 2017 but has been hit by a a series of delays. On Wednesday EDF said it would be constructed by 2025 although the subsidy agreement with the British government contains a clause allowing the plant to be completed no later than 2033.

BBC business editor Kamal Ahmed says the final investment decision, which should largely be a formality, by EDF and CGN will now be taken in the next few weeks.

The Hinkley Point project has come under fire over its cost and the delays to investment decisions and the timetable for building.

The government has also been criticised for guaranteeing a price of £92.50 per megawatt hour of electricity – more than twice the current cost (£40). – for the electricity Hinkley produces, which could mean higher bills for consumers. Even George Osborne’s father-in-law, former energy minister Lord Howell, has described the project as “one of the worst deals ever” for British consumers and industry.

The government said that 25,000 jobs will be created and enough energy to power six million homes, which is about 7% of the UK’s energy.