Irish cement maker CRH has teamed up with Mexican rival Cemex to explore a bid for all the assets industry giants Lafarge and Holcim must sell to get the go-ahead for their planned merger from competition watchdogs.

Germany’s Heidelberg Cement and Brazilian firm Votorantim Cimentos are also considering a joint bid for the entire portfolio.

These would compete with several private equity groupings that have been formed to pursue a deal for the assets, which are valued at between 4 billion and 7 billion euros.

Teaming up would allow companies to carve up the assets according to their geographic fits and will also help split the cost. A spokesman for Cemex has declined to comment on “market rumours”, while both Heidelberg Cement and CRH have declined to comment. No one at Votorantim Cimientos was immediately available for comment.

A spokeswoman for Lafarge declined to comment except to say the companies are on track to close the merger in the first half of next year. Holcim declined to comment.

Lafarge and Holcim unveiled plans in April this to create the world’s biggest cement group with $44 billion in yearly sales. But competition regulators in 15 countries, as well as the European Commission, are expected to take a hard look at the deal which brings together the world’s top two cement makers with a combined stock market value of more than $55 billion. The pair are seeking buyers for Holcim’s French activities, Lafarge’s German interests and other operations in Austria, Hungary, Romania, Serbia, Britain, Canada, the Philippines, Mauritius and Brazil.

Holcim has previously stated the two companies were seconding one senior manager each to a divestment committee to advance plans for the disposals which could involve setting up a new business as well as outright sales. In the event of any spin-off, the two managers would be the chief executive and chief financial officer of the company, says Holcim, in a move that could facilitate a sale to private equity firms.