The investment firm that acquired Roundy's Supermarkets five years ago is seeking a buyer for the chain, according to a report in yesterday's Wall Street Journal. As previously reported in SN, Robert A. Mariano, Roundy‘s chairman and chief executive officer, had been quoted last year as saying that the chain could be sold in the first half of 2007. Last week he told SN that he was not aware of any current sale discussions. The company could not be reached for comment on the latest report. According to the WSJ article, Roundy‘s could fetch as much as $2 billion, based on recent sale valuations in the industry. Since taking Roundy‘s private, Willis Stein has greatly expanded the chain‘s retail operations, which include stores under the Pic ‘n Save, Metro Market, Copps and Rainbow banners, while selling off much of its distribution operations.