French cement group Lafarge will hold a board meeting later on Tuesday to discuss potential changes to the terms of its merger deal with Swiss counterpart Holcim, a source familiar with the matter said.

The source added that the Lafarge board remained committed to negotiating only regarding the share exchange ratio, and not any change to the agreed leadership set-up that makes Lafarge head Bruno Lafont chief executive of the combined group.

"The board cannot give satisfaction to Holcim on all points," the source said. "It cannot accept both a change of parity and a taking of control."