Exhibit31.1

CERTIFICATIONPURSUANT TO 17 CFR240.13a-14PROMULGATED UNDERSECTION 302 OF THE SARBANES-OXLEYACT OF 2002

I, David N. Weidman, certify that:

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| 1.  | I have reviewed this quarterly report on Form 10-Q ofCelanese Holdings LLC; |

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| 2.  | Based on my knowledge, thisquarterly report does not contain any untrue statement of a materialfact or omit to state a material fact necessary to make the statementsmade, in light of the circumstances under which such statements weremade, not misleading with respect to the period covered by thisquarterly report; |

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| 3.  | Based on my knowledge, the financialstatements, and other financial information included in this quarterlyreport, fairly present in all material respects the financialcondition, results of operations and cash flows of the registrant asof, and for, the periods presented in this quarterly report; |

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| 4.  | The registrant's other certifying officer and I areresponsible for establishing and maintaining disclosure controls andprocedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e))for the registrant and we have: |

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|  | (a)  | designed suchdisclosure controls and procedures, or caused such disclosure controlsand procedures to be designed under our supervision, to ensure thatmaterial information relating to the registrant, including itsconsolidated subsidiaries, is made known to us by others within thoseentities, particularly during the period in which this quarterly reportis being prepared; |

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|  | (b)  | [Reserved] |

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|  | (c)  | evaluated the effectiveness of theregistrant's disclosure controls and procedures and presented inthis quarterly report our conclusions about the effectiveness of thedisclosure controls and procedures, as of the end of the period coveredby this report based on such evaluation; and |

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|  | (d)  | disclosed in this report any change in theregistrant's internal control over financial reporting (asdefined in Exchange Act Rules 13a-15(f) and 15d-15(f)) that occurredduring the registrant's most recent fiscal quarter (theregistrant's fourth fiscal quarter in the case of an annualreport) that has materially affected, or is reasonably likely tomaterially affect, the registrant's internal control overfinancial reporting; and |

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| 5.  | The registrant's othercertifying officer and I have disclosed, based on our most recentevaluation of internal control over financial reporting, to theregistrant's auditors and the audit committee ofregistrant's board of directors (or persons performing theequivalent functions): |

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|  | (a)  | all significantdeficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likelyto adversely affect the registrant's ability to record, process,summarize and report financial information; and |

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|  | (b)  | any fraud, whether or not material, that involvesmanagement or other employees who have a significant role in theregistrant's internal control over financial reporting. |

Date: August 12, 2005

/s/ David N. WeidmanDavidN. WeidmanPresident and Chief ExecutiveOfficer

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