Leading online retailer CDW is to be bought over by Madison Dearborn Partners, a private equity firm for $7.3 billion. Internet Retailer lists CDW as the #8 retailer in its Top 500 Guide and is listed as #3 for the computers and electronics segment. The company retails mostly to government agencies and businesses and had online sales of over $2 billion, an increase of 13% over the previous year’s sales. CDW and its investment bank Morgan Stanley have the right to solicit other offers in the next 30 days, which is sure to do.