Exhibit10.52

NALCO HOLDING COMPANY2004 STOCK INCENTIVEPLAN

RESTRICTED STOCK UNIT AGREEMENT

2006Grant

THIS AGREEMENT, is made effective as of February15,  2006 (the ‘‘**GrantDate**’’), between Nalco Holding Company (the"**Company**’’) and Chinh E. Chu(the"**Participant**’’).

R   E   C   I   T   A   L   S:

WHEREAS,the Company has adopted the Plan (as defined below), the terms of whichare hereby incorporated by reference and made a part of this Agreement;and

WHEREAS, the Board of Directors of the Company (the‘‘Board’’) has determined that theParticipant be granted the Restricted Stock Units provided for hereinpursuant to the Plan and the terms set forth herein.

NOW,THEREFORE, in consideration of the mutual covenants hereinafter setforth, the parties agree asfollows:

1. Definitions.    Whenever thefollowing terms are used in this Agreement, they shall have themeanings set forth below. Capitalized terms not otherwise definedherein shall have the same meanings as in thePlan.

(a)    "**Plan**’’means the Nalco Holding Company 2004 Stock Incentive Plan, as the samemay be amended, supplemented or modified from time totime.

(b)    "**Restricted StockUnit**’’ means the unfunded, unsecured right ofthe Participant to receive a share of the Company’s commonstock, par value $0.01 per share (the‘‘**Shares**’’).

2. Grantof Restricted Stock Units.    The Company hereby grants to theParticipant, subject to the terms and conditions of this Agreement andthe Plan, 3,670 Restricted Stock Units. The Participant shall notpossess any incidents of ownership (including, without limitation,dividend and voting rights) in Shares in respect of the RestrictedStock Units until such Restricted Stock Units have been distributed tothe Participant in the form of Shares.

3.    Delivery ofShares Underlying the Restricted StockUnits.

(a)    In General.    Subject toSections 3(b), 3(c) and 3(d), (i) the Company shall issue or causethere to be transferred to the Participant on January  1,2008, a number of Shares equal to the aggregate number of RestrictedStock Units granted to the Participant under this Agreement.

(b)    Change of Control.    Notwithstanding theforegoing, upon a Change of Control, the Company shall issue or causethere to be transferred, to the extent not previously cancelled orforfeited, to the Participant a number of Shares equal to the aggregatenumber of Restricted Stock Units granted to the Participant under thisAgreement.

(c)    Cancellation of Restricted StockUnits.    Upon the issuance or transfer of Shares in accordancewith this Section 3, a number of Restricted Stock Units equal to thenumber of Shares issued or transferred to the Participant shall becancelled.

(d)    Termination of Service on the Board ofDirectors.    If the Participant ceases to be a member of theBoard of Directors of the Company for any reason, the Restricted StockUnits shall be immediately canceled by the Company without any paymentor other consideration.

(e)    Registration orQualification.    Notwithstanding any other provision of thePlan or this Agreement to the contrary, absent an available exemptionto registration or qualification, a Restricted 

1

----

Stock Unit may not be delivered prior to thecompletion of any registration or qualification of the Restricted StockUnits or the Shares to which they relate under applicable state andfederal securities or other laws, or under any ruling or regulation ofany governmental body or national securities exchange that the Board orthe Company’s Compensation Committee(‘‘Committee’’) shall in its solereasonable discretion determine to be necessary oradvisable.

(f)    Certificates.    As soon aspracticable following the delivery date of the Shares subject to theRestricted Stock Units, the Company shall issue certificates in theParticipant’s name for such Shares. However, the Company shallnot be liable to the Participant for damages relating to any delays inissuing the certificates to the Participant, any loss by theParticipant of the certificates, or any mistakes or errors in theissuance of the certificates or in the certificates themselves

4. Legend on Certificates.    The certificatesrepresenting the Shares issued to the Participant upon the vesting ofthe Restricted Stock Units shall be subject to such stop transferorders and other restrictions as the Committee may deem reasonablyadvisable under the Plan or the rules, regulations, and otherrequirements of the Securities and Exchange Commission, any stockexchange upon which such Shares are listed, any applicable federal orstate laws or the Company’s Certificate of Incorporation andBylaws, and the Committee may cause a legend or legends to be put onany such certificates to make appropriate reference to suchrestrictions.

5. Transferability.    Unlessotherwise determined by the Committee, a Restricted Stock Unit may notbe assigned, alienated, pledged, attached, sold or otherwisetransferred or encumbered by the Participant otherwise than by will orby the laws of descent and distribution, and any such purportedassignment, alienation, pledge, attachment, sale, transfer orencumbrance shall be void and unenforceable against the Company or anyAffiliate; provided that the designation of a beneficiary shall notconstitute an assignment, alienation, pledge, attachment, sale,transfer or encumbrance.

6. Withholding.    The Company or its Affiliateshall have the right to withhold from any payment due or transfer madewith respect to the Restricted Stock Unit, any applicable withholdingtaxes in respect of the Restricted Stock Unit or any payment ortransfer with respect to the Restricted Stock Unit or under the Planand to take such action as may be necessary in the option of theCompany to satisfy all obligations for the payment of suchtaxes.

7. Securities Laws.    Upon theacquisition of any Shares pursuant to the vesting of the RestrictedStock Units, the Participant will make or enter into such writtenrepresentations, warranties and agreements as the Committee mayreasonably request in order to comply with applicable securities lawsor with this Agreement.

8. Notices.    Anynotice under this Agreement shall be addressed to the Company in careof its General Counsel at the principal executive office of the Companyand to the Participant at the address appearing in the personnelrecords of the Company for the Participant or to either party at suchother address as either party hereto may hereafter designate in writingto the other. Any such notice shall be deemed effective upon receiptthereof by the addressee.

9. GoverningLaw.    This Agreement shall be governed by and construed inaccordance with the laws of the State of New York, without regard toconflicts of laws.

10.    Restricted Stock Units Subject tothe Plan.    By entering into this Agreement the Participantagrees and acknowledges that the Participant has received and read acopy of the Plan. The Restricted Stock Units and the Shares receivedupon vesting are subject to the Plan. The terms and provisions of thePlan as it may be amended from time to time are hereby incorporated byreference. In the event of a conflict between any term or provisioncontained herein and a term or provision of the Plan, the applicableterms and provisions of the Plan will govern andprevail

11.    Counterparts.    This Agreement maybe executed in any number of counterparts, each of which when soexecuted shall be deemed to be an original and all of which takentogether shall constitute one and the same agreement. Any counterpartor other signature hereupon delivered by facsimile shall be deemed forall purposes as constituting good and valid execution and delivery ofthis Agreement by such party.

2

----

IN WITNESS WHEREOF, this Agreement has beenexecuted and delivered by the parties hereto.

|  | NALCOHOLDING COMPANY |
|--|----------------------|

|  | By: /s/ Stephen N.Landsman                         Its VicePresident, General Counsel & CorporateSecretary |
|--|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|  | /s/ Chinh E.Chu                                                Participant |
|--|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

3

----