Warren, Mich. — Art Van Furniture LLC officially filed for Chapter 11 bankruptcy Sunday night after announcing Thursday that it would close all of its stores. The Warren-based retailer filed with the U.S. Bankruptcy Court District of Delaware. In the filing, Art Van said it operates 169 locations, including 92 furniture and mattress showrooms and 77 freestanding mattress and specialty locations. The company expects to close the stores by May 31 and lay off all of its 3,100 employees. Multiple media outlets reported that the company has between $100 million and $500 million in both assets and liabilities.