A "challenging retail environment' and heavy debt has taken its toll on Shopko. Shopko filed for Chapter 11 bankruptcy protection, citing excess debt and ongoing competitive pressures. The retailer, which operates over 360 stores, said it will continue to operate and serve its customers, vendors, partners and employees during the restructuring process. It reported assets of less than $1 billion and liabilities between $1 billion and $10 billion. The filing was not unexpected. McKesson Corp. has said it supplied Shopko with $67 million in drugs since Nov. 11 but has not been paid since early December. This week, the Rx drug supplier asked a judge for a restraining order to keep Shopko from selling the medications it has supplied. McKesson attorney Jeff Garfinkle said during a court hearing that Shopko is expected to file for bankruptcy protection Jan. 15.