Holcim, based in Switzerland and Paris-based Lafarge SA are seeking antitrust backing for a planned $40 billion merger they want to complete by the first half of 2015. Once the transaction is finished, Holcim will have indirect control of Bamburi, which is 58.6 percent owned by two of Lafarge's units -- Fincem Holding Ltd. and Kencem Ltd., the company said in a statement today in the Nairobi-based Daily Nation newspaper.