Oct 9 - Standard & Poor's Ratings Services today corrected an error by reinstating its 'B+' issue-level rating and '2' recovery rating on Tenet Healthcare Corp.'s $1 billion 8.875% senior secured notes due 2019. The ratings were withdrawn due to an administrative error. (For the corporate credit rating rationale, see our research update on Tenet Healthcare, published Oct. 1, 2012.) RELATED CRITERIA AND RESEARCH -- Methodology: Business Risk/Financial Risk Matrix Expanded, Sept. 18, 2012