Germany’s Merck KGaA is urging Versum Materials shareholders to vote against Versum’s planned merger with Entegris at an upcoming special meeting to approve the deal. Merck has offered to acquire Versum in an all-cash deal that it says is superior for Versum shareholders. Versum and Entegris maintain that shareholders will have more upside potential by staying invested in the combined electronic materials company. The date for the shareholders meeting has not been set. Entegris and Versum have received US government antitrust clearance for the deal to go ahead.