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FORM OF
NOTICE OF GUARANTEED DELIVERY
TO TENDER FOR EXCHANGE UNREGISTERED 9 1/4% SENIOR NOTES DUE 2008
OF
MILLENNIUM AMERICA INC.
PURSUANT TO THE PROSPECTUS
DATED [ ], 2002

THE EXCHANGE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 5:00 P.M.,
NEW YORK CITY TIME, ON [ ], UNLESS EXTENDED.

THE EXCHANGE AGENT FOR THE EXCHANGE OFFER IS:
THE BANK OF NEW YORK

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By Mail: Facsimile Transmission: By Hand/Overnight Delivery:
The Bank of New York (for eligible institutions only) The Bank of New York
15 Broad Street, 16th floor (212) 235-2261 Reorganization Department
New York, New York 10007 Confirm by Telephone: 15 Broad Street, 16th floor
Attn: Bernard Arsenek (212) 235-2356 New York, New York 10007
Attn: Bernard Arsenek
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DELIVERY OF THIS NOTICE OF GUARANTEED DELIVERY TO AN ADDRESS OTHER THAN AS
SET FORTH ABOVE OR TRANSMISSION OF THIS NOTICE OF GUARANTEED DELIVERY VIA A
FACSIMILE TRANSMISSION TO A NUMBER OTHER THAN AS SET FORTH ABOVE WILL NOT
CONSTITUTE A VALID DELIVERY.

Outstanding unregistered notes must be received by the exchange agent within
three New York Stock Exchange, Inc. trading days after the date of this notice
of guaranteed delivery.

As set forth in the prospectus, dated , 2002, of Millennium America
Inc. ('Millennium America') and Millennium Chemicals Inc. ('Millennium
Chemicals') under 'The Exchange Offer -- Guaranteed Delivery Procedures,' and in
the instructions of the letter of transmittal, this form, or one substantially
equivalent hereto, or an agent's message relating to guaranteed delivery, must
be used to accept Millennium America's offer to exchange newly issued 9 1/4%
Senior Notes due 2008, which have been registered under the Securities Act of
1933, as amended, for all of its outstanding unregistered 9 1/4% Senior Notes
due 2008, if certificates representing such notes are not immediately available,
time will not permit the letter of transmittal, certificates representing such
notes or other required documents to reach the exchange agent, or the procedures
for book-entry transfer (including a properly transmitted agent's message with
respect thereto) cannot be completed, on or prior to the expiration date.

This form is not to be used to guarantee signatures. If a signature on the
letter of transmittal is required to be guaranteed by signature guarantor under
the instructions thereto, such signature guarantee must appear in the applicable
space provided in the letter of transmittal.

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Ladies and Gentlemen:

The undersigned hereby tender(s) to Millennium America, upon the terms and
subject to the conditions set forth in the prospectus and the letter of
transmittal, receipt of which is hereby acknowledged, the aggregate principal
amount of outstanding unregistered notes set forth below pursuant to the
guaranteed delivery procedures set forth in the prospectus under the caption
'The Exchange Offer -- Guaranteed Delivery Procedures.' The undersigned hereby
authorizes the exchange agent to deliver this notice of guaranteed delivery to
Millennium America with respect to the outstanding unregistered notes tendered
pursuant to the exchange offer.

The undersigned understands that tenders of the outstanding unregistered
notes will be accepted only in principal amounts equal to $1,000 or integral
multiples thereof. The undersigned also understands that tenders of the
outstanding unregistered notes pursuant to the exchange offer may be withdrawn
at any time prior to the expiration date. For a withdrawal of a tender of notes
to be effective, it must be made in accordance with the procedures set forth in
the prospectus under 'The Exchange Offer -- Withdrawal Rights.'

The undersigned understands that the exchange of any exchange notes for
outstanding unregistered notes will be made only after timely receipt by the
exchange agent of (i) the certificates of the tendered notes, in proper form for
transfer (or a book-entry confirmation of the transfer of such notes into the
exchange agent's account at The Depository Trust Company), and (ii) a letter of
transmittal (or a manually signed facsimile thereof) properly completed and duly
executed with any required signature guarantees, together with any other
documents required by the letter of transmittal (or a properly transmitted
agent's message), within three New York Stock Exchange, Inc. trading days after
the execution hereof.

The undersigned hereby represents and warrants that the undersigned
(1) accepts the terms and conditions of exchange offer as set forth in the
prospectus and the letter of transmittal, (2) is entitled to tender such notes,
and (3) has full power and authority to tender, sell, exchange, assign and
transfer the outstanding unregistered notes and to acquire exchange notes
issuable upon exchange of such tendered notes, and that when the same are
accepted for exchange, Millennium America will acquire good and marketable title
thereto, free and clear of all liens, restrictions, charges and encumbrances and
not subject to any adverse claim or right or restriction of any kind. The
undersigned will, upon request, execute and deliver any additional documents
deemed by the exchange agent or Millennium America to be necessary or desirable
to complete the exchange, assignment and transfer of the notes tendered.

All authority herein conferred or agreed to be conferred by this notice of
guaranteed delivery shall not be affected by, and shall survive, the death or
incapacity of the undersigned, and every obligation of the undersigned under
this notice of guaranteed delivery shall be binding upon the heirs, personal
representatives, executors, administrators, successors, assigns, trustees in
bankruptcy and other legal representatives of the undersigned.

In the event of a termination of the exchange offer, the notes tendered
pursuant to the exchange offer will be returned to the tendering holders
promptly (or, in the case of notes tendered by book-entry transfer, such notes
will be credited to the account maintained at The Depository Trust Company from
which such notes were delivered).

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PLEASE SIGN AND COMPLETE

Signature(s) of Registered Holder(s)
or Authorized Signatory: ...................

............................................

Name(s) of Registered Holder(s): ...........

............................................

Principal Amount of
Notes Tendered: ............................

............................................

Certificate No.(s) of
Notes (if available) .......................

............................................

Date: ............................... , 2001

Address: ...................................

............................................

Area Code and Telephone No.: ...............

............................................

If Notes will be delivered by book-entry
transfer, provide information below:

Name of Tendering
Institution: ...............................

Depositary Account No.
with DTC: ..................................

Transaction Code Number ....................

This notice of guaranteed delivery must be signed by the
holder(s) exactly as their name(s) appear(s) on
certificate(s) for notes or on a security position listing
as the owner of notes, or by person(s) authorized to
become holder(s) by endorsements and documents transmitted
with this notice of guaranteed delivery. If signature is
by a trustee, executor, administrator, guardian,
attorney-in-fact, officer or other person acting in a
fiduciary or representative capacity, such person must
provide the following information:

PLEASE PRINT NAME(S) AND ADDRESS(ES)

Name(s): ...................................................

............................................................

Capacity: ..................................................

Address(es): ...............................................

............................................................

DO NOT SEND NOTES WITH THIS FORM. NOTES SHOULD BE SENT
TO THE EXCHANGE AGENT TOGETHER WITH A PROPERLY COMPLETED AND
DULY EXECUTED LETTER OF TRANSMITTAL OR PROPERLY TRANSMITTED
AGENT'S MESSAGE.

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THE GUARANTEE BELOW MUST BE COMPLETED

GUARANTEE
(NOT TO BE USED FOR SIGNATURE GUARANTEE)

The undersigned, an 'eligible guarantor institution' within the meaning of
Rule 17Ad-15 promulgated under the Securities Exchange Act of 1934, as amended,
hereby guarantees that the notes to be tendered hereby are in proper form for
transfer (pursuant to the procedures set forth in the prospectus under 'The
Exchange Offer -- Guaranteed Delivery Procedures'), and that the exchange
agent will receive (a) such notes, or a book-entry confirmation of the transfer
of such notes into the exchange agent's account at The Depository Trust Company,
and (b) a properly completed and duly executed letter of transmittal (or
facsimile thereof) with any required signature guarantees and any other
documents required by the letter of transmittal, or a properly transmitted
agent's message, within three New York Stock Exchange, Inc. trading days after
the date of execution hereof.

The eligible guarantor institution that completes this form must
communicate the guarantee to the exchange agent and must deliver the letter of
transmittal, or a properly transmitted agent's message, and notes, or a
book-entry confirmation in the case of a book-entry transfer, to the
exchange agent within the time period described above. Failure to do so could
result in a financial loss to such eligible guarantor institution.

Name of Firm: .................................................................

Authorized Signature: .........................................................

Title: ........................................................................

Address: ......................................................................
(ZIP CODE)

Area Code and Telephone Number: ...............................................

Dated: ............................... , 2002