Exhibit 15(a)
October 1, 2008
Merrill Lynch & Co., Inc.
4 World Financial Center
New York, NY 10080
We have reviewed, in accordance with the standards of the Public Company Accounting Oversight Board
(United States), the unaudited condensed consolidated interim financial information of Merrill
Lynch & Co., Inc. and subsidiaries (Merrill Lynch) as of March 28, 2008 and for the three-month
periods ended March 28, 2008 and March 30, 2007, and have issued our report dated May 5, 2008
(which includes an explanatory paragraph relating to the restatement discussed in Note 16 to the
unaudited condensed consolidated interim financial statements), and as of June 27, 2008 and for the
three- and six-month periods ended June 27, 2008 and June 29, 2007, and have issued our report
dated August 4, 2008 (which includes explanatory paragraphs relating to the restatement discussed
in Note 16, and the transactions subsequent to the balance sheet date discussed in Note 18 to the
unaudited condensed consolidated interim financial statements). As indicated in such reports
because we did not perform an audit, we expressed no opinion on that information.
We are aware that our reports referred to above, which were included in your Quarterly Reports on
Form 10-Q for the quarters ended March 28, 2008 and June 27, 2008, are incorporated by reference in
this Registration Statement.
We also are aware that the aforementioned reports, pursuant to Rule 436(c) under the Securities Act
of 1933, are not considered a part of a Registration Statement prepared or certified by an
accountant or a report prepared or certified by an accountant within the meaning of Sections 7 and
11 of that Act.
/s/ Deloitte & Touche LLP
New York, New York