**Exhibit 12.3**

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**CERTIFICATION**

I, Carlo Ferro, certify that:

1.      I      have reviewed this annual report on Form 20-F of STMicroelectronics N.V.;

2.      Based      on my knowledge, this annual 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;

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;

4.      The      company’s other certifying officers 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)) for the company and have:

|   | 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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|   |   |                                                                                                                                                                                                                                                                                                                      |
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|   | b)     | 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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|   | c)     | 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 |

5.      The      company’s other certifying officers 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):

|   | 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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|   |   |                                                                                                                                                                                           |
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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. |

Date: March 23,    2005

|   | By:    | /s/ Carlo Ferro                                                     |
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|   |   |                                                                     |
|   |   | **Carlo Ferro**                                                     |
|   |   | **Executive Vice President            and Chief Financial Officer** |

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