NEW YORK (Standard&Poor's CreditWire) Dec. 13, 2000--Standard&Poor's today placed its ratings on Edison International, its wholly owned utility subsidiary Southern California Edison Co. (SoCalEd), and related entities on CreditWatch with negative implications (see list below). In addition, Standard&Poor's placed its ratings on Edison Mission Energy and certain affiliates on CreditWatch with negative implications (see related press release). (In a related rating action, Standard&Poor's placed its ratings on PG&E Corp. and its units on CreditWatch with negative implications. See related press release.) The CreditWatch listings for Edison International and units reflect the rapidly escalating financial burden resulting from SoCalEd's substantial undercollection of purchased power expenses attributable to the interplay between California's extraordinarily high,