NY -- Standard&Poor's CreditWire 7/7/97 -- Standard&Poor's today has placed its double-'A'-minus corporate credit and senior debt ratings, and its 'A-1'-plus commercial paper rating of the Archer Daniels Midland Co. (ADM) on CreditWatch with negative implications. In addition, Standard&Poor's has assigned its preliminary double-'A'-minus rating to ADM's $500 million shelf filing and has placed the rating on CreditWatch with negative implications. About $3.2 billion of rated debt is outstanding. The CreditWatch listing follows Standard&Poor's concerns over ADM's ramp-up in investment spending, which has reduced the high level of financial flexibility afforded by historically high levels of available cash. Over the last year, ADM has used its solid financial position and strong presence