Versum Materials Inc. (VSM) and Entegris Inc. (ENTG) - Get Report reached a deal to merge, a transaction that combines two chemical companies that make critical components for the semiconductor industry.

The Wall Street Journal first reported the news could be announced Monday.

Under the deal, shareholders of Versum Materials will receive 1.120 shares of Entegris for each existing Versum Materials share. Entegris stockholders will own 52.5% of the combined company, while Versum Materials stockholders will own 47.5%.

Versum, based on its closing stock price Friday, is valued at $35.08 a share under the deal. The stock closed up 15.9% to $36.67 on Monday, while Entegris shares rose 5.9% to $33.16.

The combined company will have a pro forma enterprise value of about $9 billion, the companies said in a statement Monday.

"We are excited to combine with Versum Materials to create a premier specialty materials company for the semiconductor and other high-tech industries,' said Entergris President and CEO Bertrand Loy. "The combined company will be ideally positioned to more effectively help our customers achieve higher yields and new levels of performance and reliability, and together, we will be well positioned to take advantage of long-term secular semiconductor growth."

Loy will serve as CEO of the combined company, which will retain the Entegris name. It will be headquartered in Billerica, Mass. 

The deal is expected to close in the second half of 2019.