Blackhawk Network Holdings Inc., the gift-card and payment services majority-owned subsidiary of grocer Safeway Inc., has announced that it has filed a registration statement with the U.S. Securities & Exchange Commission for an initial public offering of Blackhawk's Class A common stock. The IPO will consist solely of shares to be offered by existing stockholders, including Safeway Inc. The number of shares to be offered and the price range for the offering have not yet been determined.