**Exhibit 31.1**

 

**CERTIFICATIONS**

 

I, James V. Mahoney, certify that:

 

1.                                       I have reviewedthis quarterly report on Form 10-Q of The Dayton Power and Light Company;

 

2.                                       Based on myknowledge, this report does not contain any untrue statement of a material factor omit to state a material fact necessary to make the statements made, inlight of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

 

3.                                       Based on myknowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the registrant as of, andfor, the periods presented in this report;

 

4.                                       The registrant’sother certifying officer(s) and I are responsible for establishing andmaintaining disclosure 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 registrant andhave:

 

a) Designed such disclosure controls and procedures, or caused suchdisclosure controls and procedures to be designed under our supervision, toensure that material information relating to the registrant, including itsconsolidated subsidiaries, is made known to us by others within those entities,particularly during the period in which this report is being prepared;

 

b) Designed such internal control over financialreporting, or caused such internal control over financial reporting to bedesigned under our supervision, to provide reasonable assurance regarding thereliability of financial reporting and the preparation of financial statementsfor external purposes in accordance with generally accepted accountingprinciples;

 

c) Evaluated the effectiveness of the registrant’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;

 

d) Disclosed in this report any change in theregistrant’s internal control over financial reporting that occurred during theregistrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarterin the case of an annual report) that has materially affected, or is reasonablylikely to materially affect, the registrant’s internal control over financialreporting; and

 

5.                                       The registrant’sother certifying officer(s) and I have disclosed, based on our most recentevaluation of internal control over financial reporting, to the registrant’sauditors and the audit committee of the registrant’s board of directors (orpersons performing the equivalent function):

 

a) All significant deficiencies and material weaknesses in the designor operation of internal control over financial reporting which are reasonablylikely to adversely affect the registrant’s ability to record, process,summarize and report financial information; and

 

b) Any fraud, whether ornot material, that involves management or other employees who have asignificant role in the registrant’s internal control over financial reporting.

 

 
| Date:       | October 28,  2005                 |
|-------------|----------------------------------------|
| Signature:  | /s/ James V.  Mahoney                  |   |
| Print Name: | James V.  Mahoney                      |
| Title:      | President  and Chief Executive Officer |

 

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