**Exhibit        12.1**

**CERTIFICATION        OF CHIEF EXECUTIVE        OFFICER**

| I,                  Gérard Mestrallet,                  certify                  that:   |
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| 1.                                                                                                      | I                  have reviewed this annual report                  on Form 20-F of SUEZ;  |
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| 2.                                                                                                      | Based                  on my knowledge,                  this report                  does not                  contain any untrue statement of a material fact or omit to state                  a                  material fact necessary to make the statements made, in light of                  the                  circumstances under which such statements were made, not misleading                  with                  respect to the period covered                  by this                  report;  |
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| 3.                                                                                                      | Based                  on my knowledge, the financial statements, and other financial                  information                  included in this report, fairly present in all material respects                  the                  financial condition, results of operations and cash flows of the                  company                  as of, and for, the periods presented in this report;  |
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| 4.                                                                                                      | The                  company’s other certifying officer and I are responsible for establishing                  and maintaining disclosure controls and procedures (as defined                  in Exchange                  Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial                  reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f))                  for                  the company and have:  |
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|                                                                                                    | (a) | Designed                  such disclosure controls and procedures, or caused such disclosure                  controls and procedures to be designed under our supervision, to                  ensure                  that material information relating to the company, including its                  consolidated subsidiaries, is made known to us by others within                  those                  entities, particularly during the period in which this report is                  being                  prepared; |
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|                                                                                                    | (b) | Designed                  such internal control over financial reporting, or caused such                  internal                  control over financial reporting to be designed under our supervision,                  to                  provide reasonable assurance regarding the reliability of financial                  reporting and the preparation of financial statements for external                  purposes in accordance with generally accepted accounting                  principles; |
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|                                                                                                    | (c) | Evaluated                  the effectiveness of the company’s disclosure controls and procedures and                  presented in this report our conclusions about the effectiveness                  of the                  disclosure controls and procedures, as of the end of the period                  covered by                  this report based on such evaluation; and |
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|                                                                                                    | (d) | Disclosed                  in this report any change in the company’s internal control over financial                  reporting that occurred during the period covered by the annual                  report                  that has materially affected, or is reasonably likely to materially                  affect, the company’s internal control over financial reporting;                  and |
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| 5.                                                                                                      | The                  company’s other certifying officer and I have disclosed, based on our most                  recent evaluation of internal control over financial reporting,                  to the                  company’s auditors and the audit committee of the company’s board of                  directors (or persons performing the equivalent functions):  |
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|                                                                                                    | (a) | All                  significant deficiencies and material weaknesses in the design                  or                  operation of internal control over financial reporting which are                  reasonably likely to adversely affect the company’s ability to record,                  process, summarize and report financial information;                  and |
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|                                                                                                    | (b) | Any                  fraud, whether or not material, that involves management or other                  employees who have a significant role in the company’s internal control                  over financial reporting. |
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| Date:June                  29, 2007                                                           |

|   | /s/                    Gérard Mestrallet |   |
|--------|-----------------------------------------------|--------|
|   | Gérard                  Mestrallet       |   |
|   | Chief                  Executive Officer      |   |

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