Exhibit31.1

CERTIFICATIONPURSUANT TO 17 CFR 240.13a-14PROMULGATED UNDERSECTION 302 OF THE SARBANES-OXLEY ACT OF2002

I, David N. Weidman, certifythat:

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| 1.  | I have reviewed this annualreport on Form 10-K of Celanese HoldingsLLC; |

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| 2.  | Based on my knowledge, thisannual report does not contain any untrue statement of a material factor 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 annualreport; |

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| 3.  | Based on my knowledge, thefinancial statements, and other financial information included in thisannual report, 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 annual report; |

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| 4.  | The registrant's othercertifying officer and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in ExchangeAct Rules 13a-15(e) and 15d-15(e)) for the registrant and wehave: |

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| (a)  | designed such disclosure controlsand procedures, or caused such disclosure controls and procedures to bedesigned under our supervision, to ensure that material informationrelating to the registrant, including its consolidated subsidiaries, ismade known to us by others within those entities, particularly duringthe period in which this annual report is beingprepared; |

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| (b)  | [Reserved] |

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| (c)  | evaluatedthe effectiveness of the registrant's disclosure controls andprocedures and presented in this annual report our conclusions aboutthe effectiveness of the disclosure controls and procedures, as of theend of the period covered by this report based on such evaluation;and |

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| (d)  | disclosed in this report any changein the registrant'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.  | Theregistrant's other certifying officer and I have disclosed, basedon our most recent evaluation of internal control over financialreporting, to the registrant's auditors and the audit committeeof registrant'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 involves management or other employees who have a significant rolein the registrant's internal control over financialreporting. |

Date: March 31, 2006

/s/David N. WeidmanDavid N. WeidmanPresident and ChiefExecutive Officer

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