Meet the Dunsirn Partners Team

Brian Dunsirn, President and Partner

Current Chairman and CEO of all Dunsirn Partners port folio companies since 2004, Brian’s entrepreneurial approach is key to Dunsirn Partners’ ability to add value to businesses with new, innovative market ideas to provide growth. His operational and management expertise is backed by 10 years of narrow web printing experience and proven through 14 years as Founder, President and CEO of Dunsirn Industries, a company that went from a startup to a $70-million business under his tenure. Following the 2001 sale of Dunsirn Industries to Avery Dennison, Brian completed the integration of the two companies while simultaneously leading a $100-million global division. Since the foundation of Dunsirn Partners, the firm has completed 2 acquisitions, 4 add-on acquisitions, 2 start-up businesses and 2 divestures.

Tom Prosser

Tom is the retired Chairman and CEO of Menasha Corporation. His business career also included 17 years in commercial banking, serving as CEO of national banks in both Waukesha and Neenah, Wisconsin, followed by 8 years as part owner, Senior VP and COO of Hoffmaster Company, and 9 years as a Senior VP of investment banking firm R.W. Baird & Co. He has also served on a number of business, banking and charity boards, is an investor in several small businesses, and brings a breadth of experience to the deliberations of Dunsirn Partners.

Michael Pepke

Michael T. Pepke is a business lawyer in Reinhart’s Business Law Practice. Mike works with a wide array of companies in a variety of industries, but the heart of his practice is serving as general counsel to middle-market, privately owned businesses. Mike’s basic philosophy of practice is to add value to his clients’ personal and business goals beyond lawyering. To that end, he makes it his business to understand their business.

Walter Weigel

Current managing director of Kealia Bayern Corporation, a Toronto, Canada-based private equity firm, Walter has worked in Canada, the U.S. and Europe primarily in the manufacturing, contract converting, utility and chemical industries and is expert in management control systems and turnarounds.

Mark Nielsen

Mark started his career in public accounting (CPA-Wisconsin) before serving for over 20 years as CEO, President, or Executive VP for several successful small- and mid-sized companies. In these roles, Mark championed and led key strategic initiatives, including executing five acquisitions and three divestitures as well as building several new manufacturing facilities. Mark has served as a board member for a major bank and has also volunteered for many years for various charitable organizations, chairing the majority of these. Mark’s present focus is investing in private equity opportunities.


Pfingsten is an operationally focused private equity firm formed in 1989. From their headquarters in Chicago to their representative offices in ChangAn, China and New Delhi, India, they build better businesses through operational implements, professional management practices, global capabilities and profitable business growth rather than financial engineering. Dunsirn Partners has entered into a formal agreement to acquire packaging related businesses with Pfingsten.