CENTER VALLEY, PA/CARPINTERIA, CA - Avantor™ Performance Materials and NuSil™ Technology LLC, both portfolio companies of New Mountain Capital LLC, have signed a definitive agreement to merge. This merger will create the global leader in ultra-high-purity materials for the life sciences and advanced technology markets, as the demand for such materials grows due to technological advances, market expansion, and the increasingly strict regulatory and performance specifications of the life sciences and other industries.

The combined company, to be named Avantor, will provide performance materials and solutions for the production and research needs of over 6,500 customers across the biotechnology, pharmaceutical, medical device, diagnostics, aerospace and defense, and semi-conductor industries. The combination brings complementary technologies and advanced analytical capabilities together to create a portfolio of over 30,000 products that meet increasingly stringent standards across technology-driven and highly regulated markets. The company will be particularly well positioned to support the industrialization of the biopharmaceutical sector through its bioprocessing and biomaterials offerings.

"Avantor and NuSil both share a long-standing commitment to collaborate with customers to develop innovative products that meet the most stringent quality and regulatory standards," said Michael Stubblefield, CEO of Avantor. "Both companies have been highly successful and fast growing on their own, and together we will offer even more comprehensive product lines and technological advantages. We at Avantor look forward to working with the NuSil team to capture the full potential from this combination."

New Mountain initially led investments in Avantor and Nusil in 2010 and 2011, respectively. Both investments were made out of the same fund (New Mountain Partners III); New Mountain is the majority owner of both companies and will remain as the majority owner post-merger. The merger is subject to customary closing procedures and is expected to close in late September. Terms of the transaction were not disclosed.