Madison Dearborn Partners, LLC ("MDP"), based in Chicago, is one of the most experienced and successful private equity investment firms in the United States. MDP has raised over $18 billion of capital since its formation in 1992. Madison Dearborn Partners, LLC is a private equity and venture capital firm specializing in buyouts of private or publicly held companies, or divisions of larger companies; recapitalizations of family-owned or closely held companies; balance sheet restructurings; acquisition financings; and growth capital investments in mature companies. The firm prefers to invest in basic industries, communications, consumer, financial services, healthcare, and real estate sectors. Within the basic industries sectors, it focuses on energy and power, paper, packaging and forest products, chemicals, building products, metals and mining, diversified industrial, natural resources, automotive, food, refining, and general manufacturing industries. In the communications sector, the firm invests in media including broadcast television, radio station groups, and publishing companies; wireless communications sector including mobile telephone operators, paging service providers, high-capacity data and voice transmission service providers, and satellite service providers; and wireline telecommunications including local exchange carriers, rural telephone operators, and cable television system operators.