Private equity deals

Kohlberg & Company has acquired Nellson Nutraceutical LLC, an Irwindale, Calif.–based provider of branded and private-label nutraceutical products in North America. Sellers include Citigroup Private EquityGoldman Sachs and New York Life Insurance Co. www.nellsonllc.com

Action Environmental Group, a provider of solid waste services in New York and New Jersey, has acquired the New York and New Jersey hauling, transfer station and recycling assets of Interstate Waste Services, No financial terms were disclosed. The deal was primarily financed by AEG sponsors Summer Street Capital Partners and Ironwood Capital Management, while debt financing came from Comerica Bank, Webster Bank, Union bank and CoBank. IWS is a portfolio company of Highstar Capital. www.actioncarting.com

Arsenal Capital Partners has acquired International Fiber Corp., a North Tonawanda, N.Y.-based provider of in insoluble fiber products, from Swander Pace Capital. No financial terms were disclosed.www.ifcfiber.com

Distribution International Inc., a Houston-based portfolio company of Audax Group and CapStreet Group, has made two acquisitions: Certain assets of Insulation Services Inc., a Greenville, S.C.-based distributor of thermal and acoustic insulation products; and Mid-Tex Distribution Company, a San Antonio-based distributor of thermal and acoustical insulation products. No financial terms were disclosed for either deal. www.distributionintl.com

Estancia Capital Partners has acquired a minority equity stake in Sustainable Growth Advisors, a Stamford, Conn.-based traditional equity manager with approximately $5.3 billion in client assets under management. No financial terms were disclosed. www.sgadvisers.com

Pharmaceutical Product Development LLC, a contract research organization sponsored by The Carlyle Group and Hellman & Friedman, has acquired Acurian, a Horsham, Penn.–based provider of clinical trial patient enrollment and retention solutions for the life sciences industry. No financial terms were disclosed. Acurian had raised more than $30 million in VC funding early last decade from such firms as Euclid SR Partners, Flatiron Partners, JPMorgan Partners, Merck Capital Ventures, ProQuest Investment and Caisse de depot et placement de Quebec. www.acurian.com

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