By John Revill

ZURICH--Holcim Ltd. (HOLN.VX) on Tuesday said two executives have been appointed to present assets to potential buyers as the building materials manufacturer presses ahead with a $50 billion union with France's Lafarge SA (LG.FR).

Alain Bourguignon, its area manager for Canada, the U.K. and the U.S., and Marc Soule, a Lafarge senior vice president, will be seconded to a divestment committee set up by the two companies.

The appointments come as Holcim and Lafarge look to sell chunks of their businesses around the world to receive regulatory backing for their merger, which they hope to complete by the middle of 2015. The deal, which was announced this year, will create the world's biggest construction materials company by revenue, with sales of about $43 billion.

One option for the executives is to carve out the operations the companies want to sell and seek a buyer for the entire package, Holcim said. In this event, Mr. Bourguignon would be proposed as chief executive and Mr. Soule as chief financial officer of the divested assets.

Holcim said it was exploring different divestment strategies with regulators and potential buyers.

The company also said Urs Bleisch, who oversees the company's cost-cutting measures, would be nominated to its executive committee.

Write to John Revill at john.revill@wsj.com

Subscribe to WSJ: http://online.wsj.com?mod=djnwires