(Sharecast News) - Shares in Pets at Home slumped on Friday as it emerged that Canada Pension Plan Investment Board (CPPIB) has sold its entire stake in the pet supplies retailer.Bank of America Merrill Lynch said it has offloaded 54.2 million shares in the company, or 10.8%, at 148p per share.Merrill acted as sole bookrunner in connection with the placing, while Lazard was CPPIB's financial adviser.At 0955 BST, the shares were down 13.4% at 141.40p.