British chip designer and major Apple partner ARM Holdings is set to be acquired by Japanese firm Softbank for $31.4 billion, the BBC has revealed.

According to the report, the board of ARM is expected to recommend shareholders accept the offer, which amounts to a 43 percent premium on its closing market value of $22.2 billion last week.



Shares in the U.K. technology firm surged by 45 percent at the open of the London Stock Exchange this morning on news of the deal, adding $10 billion to ARM's market value.

The Cambridge-based company was founded in 1990 and employs 3,000 staff. The acquisition is said to be the biggest ever purchase of a European technology company, one that will be funded by Softbank's own cash reserves and a long-term loan from Japan's Mizuho Bank. Commenting on the deal, chairman and chief executive of Softbank, Masayoshi Son, 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. 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.

ARM designs the processors that power all of Apple's iOS devices, as well as most of Samsung's smartphones, and receives royalties on each chip made to its specifications. Last year over 15 billion ARM-designed processors were shipped, up 3 billion on the previous year.

Softbank is one of the world's biggest technology companies, having previously acquired Vodafone's Japanese operations and U.S. telecoms company Sprint. The latter $20 billion deal was the biggest foreign acquisition by a Japanese firm at the time.

Following the announcement of today's deal, ARM said it would keep its headquarters in Cambridge and double the number of its staff over the next five years. Softbank also intends to preserve the UK tech firm's organization, including its existing senior management structure and partnership-based business model.