Shares of Borders Group ( BGP) were among the NYSE's losers Friday, sliding 6% after the book retailer warned that its second-quarter loss would be wider than expected. The company also named a new chief executive. For the period ending July 29, Borders now sees a loss of 28 cents to 32 cents a share, wider than its earlier view of 10 cents to 20 cents a share. Analysts polled by Thomson First Call project a loss of 17 cents a share. In addition to charges associated with the retirement of its CEO, the company said its second-quarter results were hurt by sales trends that were below expectations. Looking ahead, Borders said that it no longer stands behind its previous full-year earnings and sales guidance. Previously, the company projected earnings of $1.42 to $1.60 a share. Borders plans to provide financial guidance for the year when it reports second-quarter results on Aug. 22. Analysts project earnings per share of $1.42. Separately, the company announced the hiring of George Jones, effective July 17. Jones, who most recently served as president and CEO of Saks' ( SKS) department store group, will replace Greg Josefowicz. In January, Josefowicz said that he planned to retire at some point during the next two years. "I am pleased to welcome George to Borders Group," Josefowicz said. "He brings a diversity and depth of retail experience with some of the largest and most revered brands in the business, as well as a demonstrated ability to build and lead successful management teams." Borders shares recently were down $1.03 to $17.25. Petco Animal Supplies ( PETC) soared 43% after the pet-supplies retailer agreed to be acquired by private equity firms Leonard Green & Partners and Texas Pacific Group for about $1.8 billion. The firms will pay $29 a share in cash, representing a 49% premium over Thursday's closing price of $19.45. The deal is expected to close by the fourth quarter. Shares were trading up $8.40 to $27.85. PetSmart ( PETM), Petco's chief competitor, rose $1.45, or 6%, to $24.92.