CDW, a private equity-backed technology products retailer, expects to price its initial public offering at between $20 and $23 per share. The company, which plans to list on the NASDAQ under the symbol CDW, is offering 23.25 million shares, and its selling shareholders are offering another 4.65 million shares. PE backers Madison Dearborn Partners and Providence Equity Partners will pare down their stakes through the offering. Based in Illinois, CDW provides technology solutions like cables, computers, monitors, projectors, and memory and data storage products for government, education and healthcare clients. The two investors took the company private in 2007 for about $7.3 billion.