Mars, Incorporated has announced a £190 million ($255 million) investment between 2023-2028 to transform its factory in Slough, Berkshire, England into a next-generation manufacturing hub. 

This follows the company's announcement in September 2025 to invest €1 billion across the EU. 

The Slough factory, the birthplace of the Mars Bar in 1932, supports the UK market and serves as a key exporter to the EU. In 2025 alone, the site exported over 2.7 million kilograms of chocolate to Ireland and over 12.3 million kilograms to the Netherlands.

The £190 million investment will introduce state-of-the-art manufacturing capabilities, combining robotics and AI with upgraded machinery, as well as advanced cooling systems and energy-efficient utilities, to improve performance and sustainability across the site. Mars will deploy digital twin technology to the Slough factory, using AI-driven data to optimize production, ensure consistency and reduce waste. The investment will also support extensive workforce upskilling, creating new routes into advanced engineering, automation and data-enabled manufacturing roles and ensuring associates have the skills needed for the future of manufacturing.

"This investment reflects our confidence in the UK as a hub to manufacture and innovate,” says Adam Grant, general manager, Mars Snacking UKI. “In taking a long-term view, we are ensuring our operations remain world-class, competitive and fit for the future. Our Slough factory is deeply rooted in our heritage, and as a proud family-owned business, we are committed to investing in a future that creates lasting, positive impact for the communities where we operate."

This latest investment in the UK is part of Mars’ broader strategy to strengthen its manufacturing and innovation footprint across Europe. With more than 90 years in Europe, Mars operates 24 factories across 10 EU countries, employing 25,700 people and exporting to over 100 markets.

Mars’ other European investments include:

• In France, Mars has invested nearly €500 million over the past five years across its eight factories to modernize production and accelerate the environmental transition. This includes renewing an ice cream production line at Steinbourg — home to Mars' only European ice cream factory — and expanding the M&M's excellence hub in Haguenau, the largest M&M's factory in Europe, with both sites exporting over 70% of their output.
• In the Netherlands, Mars continues to invest between €28 million-€30 million annually in its Veghel factory. In 2026, this includes an €18 million investment in a new milk plant and €16 million in new conches, further strengthening the site's role as a key chocolate production hub in Europe.
• In Poland, Mars is investing approximately €250 million between 2023–2027 into its Janaszówek chocolate factory. The investment will introduce automation and increase site capacity by 63%, positioning the factory as a central driver of Mars' growth ambitions in the region.

On a global scale, Mars says its long-term manufacturing strategy is focused on building modern, resilient and innovative production capabilities. This includes the previously announced plan to invest €1 billion across the EU and a further $2 billion in manufacturing in the U.S. through 2026. This strategy is further supported by Mars’ recent acquisition of Kellanova, bringing together two portfolios to accelerate growth and innovation across its snacking business.