Image: ARM Image: ARM

One of the UK's largest tech companies will be sold to a Japanese firm for £24 billion, in a move that will double the size of the business in Britain.

ARM Holdings' board will recommend its shareholders accept SoftBank's offer of around 43% above its closing share price on Friday.

The tech firm employs around 3,000 people in the UK and mainly designs microchips used in the majority of smartphones. ARM said it would keep its headquarters in Cambridge, with the total workforce growing to 6,000 over the next five years.

SoftBank, which is itself one of Japan's biggest tech companies, said it will maintain ARM's brand and senior management.

Masayoshi Son, chairman and chief executive of SoftBank, said: "This is one of the most important acquisitions we have ever made, and I expect ARM to be a key pillar of SoftBank's growth strategy going forward,

"We have long admired ARM as a world renowned and highly respected technology company that is by some distance the market leader in its field."

Chancellor Phillip Hammond said: "Britain is open for business - and open to foreign investment. Softbank's decision confirms that Britain remains one of the most attractive destinations globally for investors to create jobs and wealth.

"And as ARM's founders will testify, this is the greatest place in the world to start and grow a technology business."