Martin Marietta to combine with Lhoist unit in $13.5B deal

• Martin Marietta (NYSE:MLM) agreed to combine with Lhoist North America in a $13.5 billion cash-and-stock transaction.
• The deal creates a large U.S. lime and limestone platform with more than 2 billion tons of reserves.
• LNA reported $1.8 billion in 2025 sales and $786 million in Adjusted EBITDA.

Martin Marietta (NYSE:MLM) said it will combine with Lhoist North America in a transaction valued at about $13.5 billion, structured as a mix of cash and stock consideration.

The companies said the combined business will form a major U.S. lime and limestone platform with access to more than 2 billion tons of reserves.

Lhoist North America reported 2025 gross sales of $1.8 billion and adjusted EBITDA of $786 million, reflecting strong underlying operating margins before the transaction.

Martin Marietta said the deal is expected to be accretive to earnings and margins within the first full year after closing, which is targeted for the second half of 2026.

The transaction expands Martin Marietta’s position in construction materials by adding a large-scale lime and limestone production network across key U.S. markets.

The companies said the combination will strengthen scale and reserve life in a sector tied closely to infrastructure, construction, and industrial demand.