NEW YORK--(BUSINESS WIRE)--New Mountain Capital, LLC, (“New Mountain”), a growth-oriented private equity firm with over $20 billion in assets under management, today announced the initial public offering of New Mountain portfolio company Avantor. Avantor is a leading global provider of mission critical products and services to customers in the biopharma, healthcare, education & government and advanced technologies & applied materials industries. New Mountain formed Avantor for an enterp.