French building materials firm Saint-Gobain is to take over its Swiss rival, construction chemicals specialist Sika. The deal has met strong opposition from Sika’s management, several of whom have threatened to resign if it goes ahead.

Saint-Gobain will buy the controlling 16% of Sika’s financial shares for CHF2.75 billion (£1.8 billion) from the Burkard family, relatives Sika’s founder, thereby gaining 52% of voting rights. Sika describes the Burkard family’s control as based on the public shareholders’ trust and the family’s commitment.

Sika’s board and management say that they haven’t been consulted about the transaction and don’t see its logic or value for their company. Pierre-André de Chalendar, Saint-Gobain’s chief executive, has condemned Sika’s response as ‘emotional’ and ‘unhelpful’. He hopes for the situation to stabilise after discussions with Sika’s chairman and chief executive.

The deal is pending clearance from antitrust authorities and is part of Saint-Gobain’s push into emerging markets, where Sika makes a large proportion of its sales.