What happened
The U.S. Department of Justice said Taiheiyo Cement Corp. and its CalPortland Co. subsidiary must divest three San Diego County ready-mix concrete plants and related assets to move forward with CalPortland's planned $712 million purchase of ready-mix concrete assets from Vulcan Materials Co.
The agency said it filed a civil antitrust lawsuit in the District of Columbia federal court to block the deal, while also filing a proposed settlement that would resolve its competition concerns if approved by the court. The department said the settlement is aimed at preserving competition for ready-mix concrete, a construction input used in homebuilding, commercial construction and infrastructure projects.
According to the DOJ, CalPortland and Vulcan are two leading ready-mix concrete suppliers in San Diego County, which the agency described as already highly concentrated. The department said the transaction would likely lead to higher prices, lower quality and less favorable terms for ready-mix concrete buyers.
The DOJ said the proposed settlement requires the companies to divest the three plants to Holliday Rock Co. Inc., which the agency described as an experienced American supplier of ready-mix concrete and other building materials. The agency also said Holliday Rock is expected to hire certain CalPortland and Vulcan employees who currently support the divested businesses.
Taiheiyo is headquartered in Tokyo and operates in the United States through CalPortland, which is headquartered in Las Vegas, according to the DOJ. Vulcan is headquartered in Birmingham, Alabama, and reported approximately $7.9 billion in 2025 revenue, while Taiheiyo reported more than $5.5 billion in fiscal 2025 revenue.
The proposed settlement remains subject to Tunney Act review. The DOJ said the proposed settlement and competitive impact statement will be published in the Federal Register, followed by a 60-day comment period before the court may enter final judgment if it finds doing so is in the public interest.