Comment on S7-17-08, S7-18-08, and S7-19-08 from Mayer Brown LLP, September 4, 2008

Mayer Brown LLP71 South Wacker DriveChicago, Illinois 60606-4637Main Tel (312) 782-0600Main Fax (312) 701-7711September 4, 2008 www.mayerbrown.comBY ELECTRONIC MAILMs. Florence E. HarmonActing SecretarySecurities and Exchange Commission100 F Street, NEWashington, DC 20549Re: Security Ratings; Release Nos. 33-8940,34-58071; File No. S7-18-08References to Ratings of Nationally RecognizedStatistical Rating Organizations; Release No. 34-58070 (File No. S7-17-08)References to Ratings of Nationally RecognizedStatistical Rating Organizations; Release Nos.IC-28327, IA-2751; File No. S7-19-08Dear Ms. Harmon:Mayer Brown LLP appreciates the opportunity to comment on the referenced releases, whichpropose amendments to eliminate references to security ratings from many of the Commission’sforms and rules. We are commenting only on the proposed amendments that significantly affectasset-backed securities (ABS). Specifically, we are commenting on the Commission’s proposedchanges to: General Instruction I.B.5. to Form S-3; Rule 415(a)(1)(vii) under the Securities Act; Regulation AB; Regulation M (but only the proposed changes relating to ABS); and Rules 2a-7 and 3a-7 under the Investment Company Act.All of these changes relate directly to offerings of ABS, except for the ones relating to Rule 2a-7,which we address because of the importance of money market funds as investors in ABS. Thechanges listed in our first three bullets are proposed in Release ...