US defence giant Heico has acquired the North East defence operations of the historic steel business William Cook, in a move that creates a new joint venture and hands the American company an 80 per cent stake in one of Britain’s most strategically important military suppliers.
The deal, for an undisclosed sum, brings together Heico-Cook Defence (HCD), a new entity in which Heico holds the majority and William Cook Holdings retains 20 per cent. The venture encompasses Cook Defence Systems, William Cook Stanhope and William Cook Intermodal. All three will continue to operate from the purpose-built factory in Stanhope, County Durham, which currently employs about 130 people. The companies have confirmed that employee, customer and supplier contracts remain unaffected.
Outside the scope of the transaction, William Cook Rail, William Cook Cast Products and their subsidiaries and associates stay wholly owned by William Cook Holdings. The parent company reported a turnover of £100 million for the year to 28 June 2025. Sir Andrew Cook CBE, the industrialist who rescued the family business in the 1980s, remains chairman of William Cook Holdings, while William Cook and Chris Seymour continue as directors.
Supplying the front lines
The centrepiece of the acquisition – Cook Defence Systems – has established itself as a vital link in the supply chains of both the British Army and Ukraine’s armed forces. The company, which was created in its current form by Sir Andrew in 1994 but traces its track‑manufacturing heritage back to 1940, designs and produces mission‑critical track systems for armoured fighting vehicles. It also manufactures blast‑proof components.
Cook Defence Systems played a key role in providing replacement tracks for Ukraine’s tank fleet as the country has fought to defend itself against Russia’s full‑scale invasion. The firm is also the sole supplier of steel track to the UK Ministry of Defence, with its products fitted to every British Army fighting vehicle in service. Last year Cook Defence Systems hosted the Minister for Armed Forces, Luke Pollard, to mark a three‑year contract to supply spare tracks for all of the Army’s in‑service armoured fighting vehicles. It is additionally supplying tracks for the Army’s Challenger 3 tanks and Ajax reconnaissance vehicles. For Ajax, the company has designed a new lightweight track system.
The company’s importance extends well beyond the UK. In the year to June 2025 it exported to more than a dozen allied nations, serving over 6,000 vehicles. Its financial performance has reflected this demand: in the year to June 2024, turnover soared 59 per cent to £49.2 million, while operating profit more than doubled. The Stanhope workforce grew from 113 to 126 employees over the same period.
The broader William Cook group has also seen strong growth. William Cook Stanhope, which manufactures components for other group companies, reported a 54 per cent jump in turnover to £37.2 million for the year to June 2024, with operating profit rising more than fourfold. The parent company William Cook Holdings posted a turnover of £98.7 million in the same period, up 46.6 per cent, and a pre‑tax profit of £22 million.
A partner for growth
Hollywood, Florida‑based Heico Corporation is a technology‑driven aerospace, industrial, defence and electronics company founded in 1957. It operates through two main segments: the Flight Support Group, which designs and overhauls aircraft parts; and the Electronic Technologies Group, which produces electronic, electro‑optical and microwave systems for defence and space. Heico reported net sales of more than $4.4 billion (£3.2 billion) for its fiscal year ending 31 October 2025 – a more precise figure of $4.49 billion, up 16 per cent, with net income rising 34 per cent to $690.4 million. In the second quarter of fiscal 2026 (ending 30 April 2026), it posted record net income of $233.8 million, up 49 per cent, on revenue of $1.38 billion, up 25 per cent. Its consolidated operating margin stood at 25.5 per cent. Heico has completed over 90 acquisitions since the 1990s and said it expects the Cook Defence deal to be accretive to earnings within a year of closing.
Eric Mendelson, Heico’s co‑chairman and co‑chief executive officer, said: “Cook Defence Systems represents a distinctive addition to Heico, with many of the attractive attributes we look for in our businesses. The company has established strong relationships across leading defence OEMs and government customers across multiple critical armoured vehicle platforms. Cook’s proprietary technology, consistent aftermarket demand, and exposure to increasing global defence spending position it well for continued growth and long‑term value creation. We are pleased to welcome William Cook and his team to the Heico family.”
Sir Andrew Cook welcomed the partnership. “We are proud to have built Cook Defence Systems into a trusted partner to governments, armies and armoured vehicle manufacturers worldwide,” he said. “In Heico, we have found a long‑term partner that values our independence, supports our growth ambitions, and shares our commitment to engineering excellence, quality, and service. We are confident about the future of Cook Defence Systems under the joint ownership of Heico and William Cook Holdings.”
The acquisition comes at a time of significant change in the UK defence landscape. The Ministry of Defence, under Minister for Defence Readiness and Industry Luke Pollard, has been driving reforms to accelerate procurement and strengthen industrial partnerships. Since the general election, more than 1,200 defence contracts have been signed, with 86 per cent awarded to British companies – a figure that rose to 94 per cent of £4.9 billion in contracts signed since October. New rules tie profit rates to delivery performance, and the government has set a target to increase direct SME spend by 50 per cent by May 2028. Defence spending is also rising, with an additional £5 billion allocated this year and a commitment to reach 2.6 per cent of GDP by 2027 and 3.5 per cent by 2035. The sector has seen a surge in merger and acquisition activity globally, driven by NATO spending pledges and a European desire to reduce dependency on US supply chains.
Sir Andrew has been a vocal critic of government manufacturing strategy in the past, describing talk of a UK manufacturing resurgence as “wishful thinking” and criticising tax policies and the lack of tariffs on Chinese imports. Yet the deal with Heico positions Cook Defence Systems for a long‑term future under joint ownership. William Cook will continue to lead the operations of Heico‑Cook Defence, and Sir Andrew Cook CBE remains chairman of William Cook Holdings, with Chris Seymour continuing as a director.
