Martin Marietta Materials has agreed to acquire Lhoist North America in a transaction valued at approximately $13.5 billion, including debt. The deal was announced on Monday and represents the largest acquisition in the history of the Raleigh, North Carolina-based company.

The transaction will be funded through a combination of $7 billion in cash and $6.5 billion in shares of Martin Marietta stock. Upon closing, the Berghmans family, which controls the Lhoist Group, is expected to hold roughly 15% ownership in Martin Marietta.

Martin Marietta specializes in supplying heavy building materials such as crushed stone, sand, gravel, and asphalt for infrastructure projects including highways and sidewalks, in addition to a smaller but profitable specialty materials segment that produces products like dolomitic lime. Lhoist North America, headquartered in Fort Worth, Texas, is a manufacturer and supplier of lime, limestone, and related mineral-based products. It operates as part of the privately held Belgian industrial company Lhoist Group, which has roots extending back to 1889.

Lime is an important raw material used in a variety of industries, including water treatment, agriculture, and steel production. The combined company expects to benefit from growing demand driven by infrastructure projects, including data-center construction and semiconductor manufacturing facilities in the United States.

Martin Marietta’s aggregates business, which centers on high-volume construction materials, has delivered strong financial performance in recent years. Lhoist’s North American operations are concentrated in the U.S. Sunbelt region—a key market area that Martin Marietta has identified as critical to its long-term growth strategy.

Ward Nye, who has been CEO of Martin Marietta since 2010, has expanded the company primarily through smaller, local acquisitions as part of an ongoing growth strategy. This latest large-scale acquisition marks a significant shift toward a more transformative deal.

The building materials industry has seen increased consolidation, highlighted by Quikrete Holdings’ announcement in late 2024 of an $11.5 billion deal to acquire Summit Materials. Meanwhile, major retailers Home Depot and Lowe’s have also pursued acquisitions to strengthen their positions amid rising demand for construction materials.

Martin Marietta’s shares fell nearly 6% on the day of the announcement, despite the company’s stock having rallied more than 70% over the past five years and reaching record highs earlier this year. The deal underscores a broader trend of consolidation as companies seek to scale operations and capture growth opportunities in infrastructure and industrial markets.