Exhibit 99.2
                                                                    ------------

                           LYONDELL CHEMICAL COMPANY

                               Letter to Clients
                                      for
                           Tender of All Outstanding

                     9 1/2% Senior Secured Notes due 2008
                          in exchange for registered
                     9 1/2% Senior Secured Notes due 2008


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The Exchange Offer will expire at 5:00 p.m., New York City time, on __________,
2002 (the "Expiration Date"), unless sooner terminated or extended. Outstanding
Notes tendered in the Exchange Offer may be withdrawn at any time before
5:00 p.m., New York City time, on the Expiration Date for the Exchange Offer.
- --------------------------------------------------------------------------------

To Our Clients:

         We are enclosing with this letter a prospectus dated ___________, 2002
(the "Prospectus") of Lyondell Chemical Company (the "Issuer") and the related
Letter of Transmittal. These two documents together constitute the Issuer's
offer to exchange its 9 1/2% Senior Secured Notes due 2008 (the "New Notes"),
the issuance of which has been registered under the Securities Act of 1933, as
amended (the "Securities Act"), for a like principal amount of issued and
outstanding unregistered 9 1/2% Senior Secured Notes due 2008, (the "Outstanding
Notes"). The exchange of Outstanding Notes for New Notes and the related
documentation are referred to herein as the "Exchange Offer."

         The Exchange Offer is not conditioned upon any minimum aggregate
principal amount of Outstanding Notes being tendered for exchange.

         We are the holder of record of Outstanding Notes held by us for your
own account. A tender of your Outstanding Notes held by us can be made only by
us as the record holder according to your instructions. The Letter of
Transmittal is furnished to you for your information only and cannot be used by
you to tender Outstanding Notes held by us for your account.

         We request instructions as to whether you wish to tender any or all of
the Outstanding Notes held by us for your account under the terms and conditions
of the Exchange Offer. We also request that you confirm that we may, on your
behalf, make the representations contained in the Letter of Transmittal.

         Under the Letter of Transmittal, each holder of Outstanding Notes will
represent to the Issuer that:

         .  such person is not an "affiliate," as defined in Rule 405 under the
            Securities Act, of the Issuer or a broker-dealer tendering
            Outstanding Notes acquired directly from the Issuer for its own
            account;

         .  if such person is not a broker-dealer or is a broker-dealer but will
            not receive New Notes for its own account in exchange for
            Outstanding Notes, it is not engaged in, and does not intend to
            participate in, a distribution of the New Notes;

         .  such person does not have an arrangement or understanding with any
            person to participate in the distribution of the Outstanding Notes
            or the New Notes within the meaning of the Securities Act;

         .  any New Notes received are being acquired in the ordinary course of
            business of the person receiving such New Notes; and

         .  if such person is a broker-dealer who will receive New Notes for its
            own account in exchange for Outstanding Notes, it will represent
            that the Outstanding Notes to be exchanged or New Notes were

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            acquired as a result of market-making activities or other trading
            activities, and that it will deliver a Prospectus in connection with
            any resale of those New Notes; however, by so acknowledging and by
            delivering a Prospectus, it will not be deemed to admit that it is
            an "underwriter" within the meaning of the Securities Act.

                                               Very truly yours,

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Please return your instructions to us in the enclosed envelope within ample time
to permit us to submit a tender on your behalf before the Expiration Date.

                                INSTRUCTION TO
                           DTC TRANSFER PARTICIPANT

To Participant of The Depository Trust Company:

         The undersigned hereby acknowledges receipt and review of the
prospectus dated ____________, 2002 (the "Prospectus") of Lyondell Chemical
Company (the "Issuer") and the related Letter of Transmittal. These two
documents together constitute the Issuer's offer to exchange its 9 1/2% Senior
Secured Notes due 2008 (the "New Notes"), the issuance of which has been
registered under the Securities Act of 1993, as amended (the "Securities Act"),
for a like principal amount of its issued and outstanding unregistered 9 1/2%
Senior Secured Notes due 2008 (the "Outstanding Notes"). The exchange of
Outstanding Notes for New Notes and the relevant documentation are referred to
herein as an "Exchange Offer."

         This will instruct you, the registered holder and DTC participant, as
to the action to be taken by you relating to the Exchange Offer for the
Outstanding Notes held by you for the account of the undersigned.

         The aggregate principal amount of the Outstanding Notes held by you for
the account of the undersigned is (fill in amount):

- --------------------------------------------------------------------------------
           Title of Series                        Principal Amount
- --------------------------------------------------------------------------------
Lyondell Chemical Company
9 1/2% Senior Secured Notes due 2008
- --------------------------------------------------------------------------------

         With respect to the Exchange Offer, the undersigned hereby instructs
you (check appropriate box):

[_]      To TENDER all Outstanding Notes held by you for the account of the
         undersigned.

[_]      To TENDER the following amount of Outstanding Notes held by you for the
         account of the undersigned:

- --------------------------------------------------------------------------------
           Title of Series                        Principal Amount
- --------------------------------------------------------------------------------
Lyondell Chemical Company
9 1/2% Senior Secured Notes due 2008
- --------------------------------------------------------------------------------
[_]      NOT to TENDER any Outstanding Notes held by you for the account of the
         undersigned.

         If no box is checked, a signed and returned Instruction to DTC
Participant will be deemed to instruct you to tender all Outstanding Notes held
by you for the account of the undersigned.

         If the undersigned instructs you to tender the Outstanding Notes held
by you for the account of the undersigned, it is understood that you are
authorized to make, on behalf of the undersigned (and the undersigned, by its
signature below, hereby makes to you), the representations contained in the
Letter of Transmittal that are to be made with respect to the undersigned as a
beneficial owner, including, but not limited to, the representations that:

         (i)      the undersigned is not an "affiliate," as defined in Rule 405
                  under the Securities Act, of the Issuer or a broker-dealer
                  tendering Outstanding Notes acquired directly from the Issuer
                  for its own account;

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         (ii)     if the undersigned is not a broker-dealer or is a
                  broker-dealer but will not receive New Notes for its own
                  account in exchange for Outstanding Notes, it is not engaged
                  in, and does not intend to participate in, a distribution of
                  New Notes;

         (iii)    the undersigned does not have an arrangement or understanding
                  with any person to participate in the distribution of the
                  Outstanding Notes or the New Notes within the meaning of the
                  Securities Act;

         (iv)     any New Notes received are being acquired in the ordinary
                  course of business of the undersigned; and

         (v)      if the undersigned is a broker-dealer that will receive New
                  Notes for its own account in exchange for Outstanding Notes,
                  it will represent that the Outstanding Notes to be exchanged
                  for New Notes were acquired as a result of market-making
                  activities or other trading activities, and it will
                  acknowledge that it will deliver a Prospectus in connection
                  with any resale of those New Notes; however, by so
                  acknowledging and by delivering a Prospectus, the undersigned
                  will not be deemed to admit that it is an "underwriter" within
                  the meaning of the Securities Act.

                                   SIGN HERE

Name of beneficial owner(s):____________________________________________________

Signature(s):___________________________________________________________________

Name(s) (please print):_________________________________________________________

Address:________________________________________________________________________

Telephone Number:_______________________________________________________________

Taxpayer Identification or Social Security Number:______________________________

Date:___________________________________________________________________________

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