NEW YORK (Reuters) - Technology products retailer CDW, which was taken private by Madison Dearborn Partners LLC and Providence Equity Partners for$7.3 billion in 2007, has hired banks for an initial public offering later this year, people familiar with the matter said. CDW, which sells products from companies including Apple, Hewlett-Packard and International Business Machines online and through its catalog, has hired JPMorgan Chase & Co, Barclays PLC and Goldman Sachs Group to lead the offering, the people said on Thursday. ...