Washington - Ken Rosenthal, a former baseball columnist for the Baltimore Sun and current senior baseball writer for FOXSports.com, has signed with XM Satellite Radio to become a weekly contributor on its baseball talk radio channel, MLB Home Plate. Beginning this week, Rosenthal will appear on XM's "Baseball This Morning" with hosts Mark Patrick, Buck Martinez and Orestes Destrade. He will also make appearances on "Baseball Beat" with host Charley Steiner, and will also appear on the channel when major news breaks on or off the field.