National Grid, one of the world’s largest energy companies, is planning to put its UK property arm up for sale for more than £800m.

National Grid Property, which owns around 2,500 acres on more than 500 brownfield sites, will be sold by its parent company as part of an ongoing disposal of surplus assets.

The sale will also include the property team of around 80 people, headed by director Phil Kirby, which manages more than 675 buildings with 840 tenancies.

The sale is thought to be the largest-ever property disposal by an former publicly owned company. The sites, a large proportion of which have planning permission, are mainly residential and could make a significant contribution to the prime minister’s 3 million housing target by 2021. There are also sites with office and industrial use potential.

A spokesperson for National Grid Property confirmed: ‘National Grid is investigating a sale of the non-operational property portfolio part of the business in the UK, as part of its strategy to focus on its core business: operating US and UK electricity and gas networks.’

DTZ has been hired to advise on the sale. It has begun testing the market and has received a number of approaches.