Versum Materials Inc. said it plans to combine with Entegris Inc. in a merger that unites two chemical companies that make critical components for the semiconductor industry.

Versum and Entegris announced Monday a stock-for-stock merger in which Versum stockholders will receive 1.120 shares of Entegris for each existing Versum share. Upon completion of the merger, Entegris stockholders will own 52.5% of the combined company, and Versum stockholders 47.5%.