NEW YORK (Standard&Poor's) Dec. 17, 2012--Standard&Poor's Ratings Services today assigned its 'A-' rating to Precision Castparts Corp.'s (A-/Stable/A-1) proposed issuance of senior unsecured notes. The company plans to issue up to a total of $3 billion of three-, five-, 10-, and 30-year notes, and will use the proceeds to fund the pending acquisition of Titanium Metals Corp. (Timet; not rated) and general corporate purposes. Precision Castparts announced the acquisition last month and expects it to close by the end of the year. We affirmed our ratings on Precision Castparts on Nov. 12, 2012, citing our expectations that credit ratios, which will decline materially from currently very strong levels following the proposed acquisition, will return to levels