Holcim and Lafarge said on October 28 that they had formally notified the European Commission of their merger plans, which would create the world's largest cement group.
The move marks the beginning of official censorship in Europe. The deal was destined from the start to be accompanied by the disposal of billions of dollars of assets for approval by global regulators.
The commission is due to rule on the deal on December 15.
Company executives told reporters in a conference call that the merger requires regulatory approval from around the world and has been approved in seven countries.
The merger will create a group with annual sales of more than $40 billion. The two companies said in a joint statement that they had fine-tuned the disposal plan for the European region after discussions with the European Commission.
The companies plan to keep Lafarge's Mannersdorf cement plant in Austria and divest all of Holcim's assets in Slovakia.
In addition, the two companies said they were in talks with potential buyers of the assets and that they intended to complete the deal, which was announced in April, in the first half of 2015.
In a conference call with reporters, Lafarge CEO Bruno Lafont and Holcim CEO Bernard Fontana declined to disclose the value of the assets sold or the offers received, but Lafont said the assets sold accounted for about 12% of the two companies' total sales.
The two companies had combined sales of about 31.5 billion euros ( $40.5 billion) in 2013.
Irish cement producer CRH teamed up with Mexican rival Cemex in early October in an attempt to bid for all the assets Lafarge and Holcim plan to sell, people familiar with the matter told reporters.
Germany's HeidelbergCement and Brazil 's Votorantim Cimentos are also considering a joint bid for all of the assets being sold, the source said.
The alliance in the building materials industry will compete with several private equity groups for assets worth between 4 billion euros and 7 billion euros ( $5 billion to $8.85 billion), according to people familiar with the matter.
Between them, Lafarge and Holcim have issued about 20 notices of the merger. So far, they have received regulatory approvals in Russia, Ukraine, Turkey, South Africa, Morocco, Kenya and Singapore.