<PAGE>
                                  EXHIBIT 99.3

            REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We have examined management's assertion, included in the accompanying Report of
Management on Compliance, that The Bank of New York (the "Company") complied
with the PPLUS Minimum Servicing Standards (attached) as of and for the year
ended December 31, 2004 as it relates to PreferredPLUS Trust Series NAI-1.
Management is responsible for The Bank of New York's compliance with those
requirements. Our responsibility is to express an opinion on management's
assertion about The Bank of New York's compliance based on our examination.

Our examination was conducted in accordance with attestation standards
established by the American Institute of Certified Public Accountants and,
accordingly, included examining, on a test basis, evidence about the Company's
compliance with those requirements and performing such other procedures as we
considered necessary in the circumstances. We believe that our examination
provides a reasonable basis for our opinion. Our examination does not provide a
legal determination on the Company's compliance with specified requirements.

In our opinion, management's assertion that The Bank of New York complied with
the aforementioned requirements as of and for the year ended December 31, 2004
is fairly stated, in all material respects.


Ernst & Young LLP

New York, New York
March 14, 2005


<PAGE>

                       REPORT OF MANAGEMENT ON COMPLIANCE


March 14, 2005


We, as members of management of The Bank of New York, (the "Company") are
responsible for complying with the requirements of the PPLUS Minimum Servicing
Standards as it relates to PreferredPLUS Trust Series NAI-1. We also are
responsible for establishing and maintaining effective internal control over
compliance with the PPLUS Minimum Servicing Standards. We have performed an
evaluation of the Company's compliance with the requirements of PPLUS Minimum
Servicing Standards as it relates to PreferredPLUS Trust Series NAI-1 as of
December 31, 2004 and for the year ended December 31, 2004. Based on this
evaluation, we assert that for the year ended December 31, 2004, the Company
complied with the requirements of the PPLUS Minimum Servicing Standards
(attached).








                                                   /s/ Robert L. Griffin
                                                   -----------------------------
                                                   Robert L. Griffin
                                                   Managing Director



                                                   /s/ Kevin Cremin
                                                   -----------------------------
                                                   Kevin Cremin
                                                   Vice President
<PAGE>

                                   APPENDIX I


                   PPLUS Minimum Servicing Standards intended
                      for use in connection with the Annual
                           Accountants Report ("AAR")

Below is Merrill Lynch Depositor, Inc.'s ("the Depositor") together with Merrill
Lynch High Grade Credit Management ("HGCM") and the Merrill Lynch Credit
Derivative Integrated Support Solutions ("ISS"), minimum servicing standards for
the PreferredPlus Program ("PPlus"). The Bank of New York ("the Bank") acts as
Trustee, Custodian, Paying Agent, and Transfer Agent on behalf of the PPlus
Program and has agreed to comply with these minimum servicing standards.


MERRILL LYNCH DEPOSITOR, INC.'S MINIMUM SERVICING STANDARDS


1. CUSTODIAL BANK ACCOUNT RECONCILIATIONS

   o  The Bank must reconcile all related custodial bank accounts.

   o  The Bank will include the Distribution report as Exhibit 99.1 in the Form
      8-Ks filed with the SEC.

2. VERIFICATION OF INCOMING TRUST COLLATERAL INTEREST PAYMENTS

   o  The Bank must have a tickler system in place so that they will be
      expecting and monitoring the custodial bank account for receipt of the
      collateral coupon interest. Each of the tickler systems shall be updated
      on an on-going basis as each new trust series is created.

   o  The Bank will ensure all interest payments are deposited into the
      custodial bank accounts and related bank clearing accounts on the day the
      Bank is in receipt of the funds.

   o  The Bank must prove the arithmetic accuracy of the amount of interest
      received by the Trust from the underlying securities and ensure that the
      face amount, description, coupon rate, and maturity date of the securities
      held in the Trust agree to the PPM Supplement dated Date XX, 20XX.

3. TRUST DISBURSEMENTS

   o  The Bank must prove the arithmetic accuracy of the amount of interest to
      be paid by the Trust to the Debt Unit holders by referring to the PPM
      Supplement dated Date XX, 20XX.

   o  The Bank will make all disbursements via wire transfer to The Depository
      Trust Company ("DTC") on the scheduled trust distribution date as soon as
      the amount of interest received from the underlying collateral into the
      custodial bank account has been received and verified for accuracy.

                                       1
<PAGE>

4. PARTIAL REDEMPTIONS

   o  If there is a partial redemption of the trust certificates the Bank and
      the Depositor must ensure that the redemption proceeds received by the
      trust and distributed by the Bank are in accordance with the series
      supplement.

5. DEFAULTS

   o  If the Bank has actual knowledge of an event of default on the underlying
      securities that did not cause the trust to liquidate, the Bank must
      distribute a formal notice of default to the Depositor, the
      certificateholders, the rating agencies and HGCM/ISS.

   o  If the Bank has actual knowledge of an event of default on the underlying
      securities that did not cause the Trust to liquidate, the procedures for a
      vote or consent of the certificateholders as set forth in the Standard
      Terms and series Supplement must be complied with.

6. CALL WARRANT EXERCISES AND OPTIONAL EXCHANGES

   o  If there is an exercise of call warrants or an optional exchange of trust
      certificates for underlying securities that did not cause the trust to
      liquidate, the Bank must give the Depositor and the affected
      certificateholders notice of any exercise of call warrants or optional
      exchange. Such notice must contain the amount of certificates to be
      purchased, the call price, and any other relevant information.

   o  If there is an exercise of call warrants or an optional exchange of trust
      certificates for underlying securities that did not cause the trust to
      liquidate, the Bank must notify the rating agencies of the call exercise
      or optional exchange.

   o  If there is an exercise of call warrants or an optional exchange of trust
      certificates for underlying securities that did not cause the trust to
      liquidate, the Bank must give notice of exercise or optional exchange to
      the Depositor and certificate registrar of any certificates that were
      called.

7. COMMUNICATIONS WITH CERTIFICATEHOLDERS

   o  If there was any occasion for the exercise of voting rights or giving
      consents by the certificateholders, the Bank must provide notice to the
      certificateholders within 5 business days of the Trust's receipt of notice
      of the occasion and the Bank must vote or give consents as directed by
      certificateholders.

                                       2