Exhibit 31(b)



                                 CERTIFICATION
                Pursuant to Section 302 of the Sarbanes-Oxley Act


         I, Kevin P. Larson, certify that:

1.       I have reviewed the annual report on Form 10-K for the year ended
         December 31, 2003 of UniSource Energy Corporation;

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 annual
                report;

3.              Based on my knowledge, the financial statements, and other
                financial information included in this annual report, fairly
                present in all material respects the financial condition,
                results of operations and cash flows of the registrant as of,
                and for, the periods presented in this annual report;

4.              The registrant'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 registrant and have:

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

                b.    evaluated the effectiveness of the registrant'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 annual report based on such evaluation;
                      and

                c.    disclosed in this annual report any change in the
                      registrant's internal control over financial reporting
                      that occurred during the registrant's most recent fiscal
                      quarter (the registrant's fourth fiscal quarter in the
                      case of an annual report) that has materially affected, or
                      is reasonably likely to materially affect, the
                      registrant's internal control over financial reporting;
                      and

5.              The registrant's other certifying officers and I have disclosed,
                based on our most recent evaluation of internal control over
                financial reporting, to the registrant's auditors and the audit
                committee of the registrant's board of directors (or persons
                performing the equivalent function):

                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 registrant's ability to record, process, summarize and
                      report financial information; and

                b.    any fraud, whether or not material, that involves
                      management or other employees who have a significant role
                      in the registrant's internal control over financial
                      reporting.


Date:    March 15, 2004     /s/
         --------------    -----------------------------------------------------
                           Kevin P. Larson
                           Chief Financial Officer, Vice President and Treasurer