AMR Corp. and its American Airlines Inc. subsidiary filed for Chapter 11 bankruptcy this morning after negotiations with American's unions failed to secure cost-saving contracts management had sought. We are lowering our ratings, including the corporate credit ratings on both entities to 'D' from 'CCC+', and removing those ratings from CreditWatch, where we placed them with negative implications Nov. 17, 2011. We expect that AMR and American will be able to reorganize in Chapter 11 and emerge as a somewhat smaller airline with more competitive labor costs and a lighter debt load. NEW YORK (Standard&Poor's) Nov. 29, 2011--Standard&Poor's Ratings Services said today that it lowered its ratings on AMR Corp. and American Airlines Inc., including the