UK chip designer ARM has agreed to a whopping buyout offer from Japanese telecoms giant SoftBank for £24.3 billion (~$32 billion)—the deal comes just weeks after Brits voted to exit the European Union.

SoftBank said it would retain ARM's senior management team, brand, and lucrative partnership-based business model.

ARM will remain headquartered in Cambridge, and SoftBank has vowed to double the staff headcount in the UK over the next five years. The smartphone chip designer currently has 4,064 employees on its books worldwide.

SoftBank chief Masayoshi Son said: "ARM will be an excellent strategic fit within the SoftBank group as we invest to capture the very significant opportunities provided by the 'Internet of Things.'" He described the acquisition—the largest tech buyout of its kind in Europe—as "one of the most important" moves in the history of its Japan-based business.

ARM chairman Stuart Chambers said that the "compelling offer" would be a shot in the arm for the company's shareholders who stand to see a 43 percent premium to its closing price of £11.89 on Friday, with SoftBank paying £17 in cash for each share.

Freshly installed chancellor of the exchequer Philip Hammond welcomed the deal. On Monday morning, he tweeted: "Decision by SoftBank to invest in @ARMHoldings shows UK has lost none of its allure to global investors—Britain is open for business," before adding, "This would be largest ever Asian investment into the UK & would double size of ARM's UK workforce. Big vote of confidence in British business."

Shares in ARM rocketed more than 40 percent on the London Stock Exchange following confirmation of SoftBank's multi-billion pound takeover plan. They are currently trading just shy of £17 a share.