NEW YORK (Standard&Poor's) Sept. 23, 2002-- Standard&Poor's Ratings Services said today that it assigned its triple-'B'-minus rating to FMC Corp.'s proposed $550 million senior secured credit facilities and affirmed its triple-'B'-minus corporate credit rating on the diversified chemical company. The outlook is revised to negative from stable. At the same time, Standard&Poor's assigned its double-'B'-plus rating to FMC's proposed $300 million senior secured notes due 2009 and lowered the ratings on its existing senior unsecured notes from triple-'B'-minus to double-'B'-plus. The downgrade reflects the noteholders' diminished recovery prospects in a default and liquidation scenario, pro forma for completion of the refinancing plan that will provide the holders of bank obligations with a first-priority claim