Hewlett-Packard's board has ended an advisory relationship with Larry Sonsini, it was reported Thursday. After the year's end Sonsini and the firm he helped build, Wilson Sonsini Goodrich & Rosati, will no longer serve as outside counsel to the board, although the law firm will still do legal work for HP. Meanwhile, the congressional panel investigating HP's boardroom spying probe has demanded that CEO Mark Hurd explain $1.37 million worth of options he exercised just before the scandal became public.