NEW YORK (Standard&Poor's CreditWire) Oct. 22, 1999--Standard&Poor's today placed its single-'B'-plus corporate credit and bank loan ratings, as well as its single-'B'-minus subordinated debt rating, for Iron Mountain Inc. on CreditWatch with positive implications. The preliminary single-'B'-plus/single-'B'-minus rating on the company's shelf registration also was placed on CreditWatch with positive implications. Additionally, Standard&Poor's placed its single-'B'-plus corporate credit rating, single-'B'-minus subordinated debt rating, and double-'B'-minus bank loan rating for Pierce Leahy Corp. on CreditWatch with positive implications. The single-'B'-minus rating on Pierce Leahy Command Co.'s senior unsecured notes (guaranteed by Pierce Leahy Corp.) was also placed on CreditWatch with positive implications. The CreditWatch listings reflect the companies' announcement of a $1.2 billion merger. Merger