The Justice Department’s Anti-trust Division has announced that it will require Taiheiyo Cement Corporation and its subsidiary CalPortland Company to divest three ready-mix concrete plants along with related assets to address anti-trust concerns arising from CalPortland’s proposed $712 million acquisition of ready-mix concrete assets from Vulcan Materials Company.

The civil anti-trust lawsuit has been filed in the U.S. District Court for the District of Columbia to block the proposed transaction, a statement on Thursday said.

At the same time, the proposed settlement filed alongside the complaint, if approved by the court, will address competitive concerns that the transaction would likely cause higher prices, lower quality, and less favorable terms for buyers of ready-mix concrete.

“Ready-mix concrete is a key input for construction and infrastructure projects across the country that are critical to strengthening the American economy,” said acting assistant attorney general Omeed Assefi of the anti-trust division.

Mr Assefi stated that the division’s pursuit of “structural remedies” in the case would provide a signal to the broader market about how to structure transactions that deliver efficiency to the market while protecting competition that benefits consumers.

As alleged in the complaint, CalPortland and Vulcan are two of the leading suppliers of ready-mix concrete in San Diego County, already a highly concentrated market.

Ready-mix concrete is essential to home construction, where it is used in foundations, driveways, patios, and swimming pools; commercial construction, where it is used in offices, hotels, warehouses, multi-family residences, and other commercial businesses; and infrastructure projects like bridges, tunnels, and highways.

The proposed settlement requires CalPortland and Vulcan to divest three ready-mix concrete plants in San Diego County to Holliday Rock Co., Inc., an American company with significant experience in ready-mix concrete and other building materials.

Holliday Rock is expected to hire certain key CalPortland and Vulcan employees that today support the divested businesses.

Taiheiyo is a Japanese corporation with its headquarters in Tokyo. Taiheiyo operates in the United States through CalPortland, a corporation with its headquarters in Las Vegas, Nevada.

Taiheiyo reported total revenues of more than $5.5 billion for fiscal year 2025.

Vulcan is a corporation with headquarters in Birmingham, Alabama. In 2025, Vulcan reported total revenues of approximately $7.9 billion.

As required by the Tunney Act, the proposed settlement, along with a competitive impact statement, will be published in the Federal Register. Any person may submit written comments concerning the proposed settlement within 60 days following the publication.