Groupon, Inc., an e-commerce site used by merchants to offer customers daily discounts, filed on Thursday with the SEC to raise up to $750 million in an initial public offering. The Chicago, IL-based company, which was founded in 2008 and booked $1.3 billion in sales for the 12 months ended March 31, 2011, plans to list under the symbol GRPN. Morgan Stanley, Credit Suisse, and Goldman, Sachs & Co. are the lead underwriters on the deal. No pricing terms were disclosed.