ARM Holdings, the firm behind the design for Apple's iPhone processors, is to be sold to Japanese company Softbank in a deal worth £24bn ($32bn).
One of Britain's biggest tech firms, Cambridge-based ARM designs microchips which are used in billions of devices including phones from Apple and Samsung.
Its sale to Softbank is based on a price of £17 per ARM share, with the company's board of directors confirming it will unanimously recommend the deal to shareholders.
Softbank, which already owns a slew of big tech companies, one of which is US mobile network provider Sprint, says ARM's headquarters will remain in Cambridge.
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ARM designs the chips which are used in numerous smartphones, including iPhones
The number of employees will also apparently double from 3,000 to 6,000 over the next five years, with more non-UK staff to be taken on.
According to ARM, the company's 'culture, brand, and DNA' will be preserved as part of the deal, with the current senior management structure to remain untouched.
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."
Mr Son also spoke about his firm's ambitions to use ARM tech to expand into the Internet of Things: "ARM will be an excellent strategic fit with the Softbank group as we invest to capture the very significant opportunities provided by the internet of things"
As ARM is perhaps the UK's most important tech company, many will be concerned about it losing its independence.
Previous deals have seen other big Cambridge-based tech firms, Autonomy and Cambridge Silicon Radio (CSR), swallowed up by HP and Qualcomm respectively.
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