**Exhibit 99.6**

 

**CERTIFICATIONPURSUANT TO RULE 13a-14 OR 15d-14 OF THE SECURITIES EXCHANGE ACT OF 1934**

 

I, Todd Takeyasu, certify that:

 

1.               I have reviewedthis annual report on Form 40-F of Penn West Energy Trust;

 

2.               Basedon my knowledge, this report does not contain any untrue statement of amaterial fact or omit to state a material fact necessary to make the statementsmade, in light of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

 

3.               Basedon my knowledge, the financial statements, and other financial informationincluded in this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the issuer as of, and for,the periods presented in this report;

 

4.               The issuer’s othercertifying officer and I are responsible for establishing and maintainingdisclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) and internal control over financial reporting (as defined inExchange Act Rules 13a-15(f) and 15d-15(f)) for the issuer and have:

 

(a)                                 Designed such disclosure controls andprocedures, or caused such disclosure controls and procedures to be designedunder our supervision, to ensure that material information relating to theissuer, including its consolidated subsidiaries, is made known to us by otherswithin those entities, particularly during the period in which this report isbeing prepared;

 

(b)                                 Designed such internal control overfinancial reporting, or caused such internal control over financial reportingto be designed under our supervision, to provide reasonable assurance regardingthe reliability of financial reporting and the preparation of financialstatements for external purposes in accordance with generally acceptedaccounting principles;

 

(c)                                  Evaluated the effectiveness of the issuer’sdisclosure controls and procedures and presented in this report our conclusionsabout the effectiveness of the disclosure controls and procedures, as of theend of the period covered by this report based on such evaluation; and

 

(d)                                 Disclosed in this report any change inthe issuer’s internal control over financial reporting that occurred during theperiod covered by the annual report that has materially affected, or isreasonably likely to materially affect, the issuer’s internal control overfinancial reporting; and

 

5.               Theissuer’s other certifying officer and I have disclosed, based on our mostrecent evaluation of internal control over financial reporting, to the issuer’sauditors and the audit committee of the issuer’s board of directors (or personsperforming the equivalent function):

 

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(a)          Allsignificant deficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likely toadversely affect the issuer’s ability to record, process, summarize and reportfinancial information; and

 

(b)         Any fraud,whether or not material, that involves management or other employees who have asignificant role in the issuer’s internal control over financial reporting.

 

Dated:             March 26, 2008

 
|   | /s/ Todd Takeyasu                                                                 |
|--------|-----------------------------------------------------------------------------------|
|   |                                                                              |
|   | Todd Takeyasu                                                                     |
|   | Executive Vice President and Chief Financial  Officer of Penn West Petroleum Ltd. |

 

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