AMENDMENT NO. 1 TO UNISOURCE ENERGY CORPORATION OFFICER CHANGE IN CONTROL AGREEMENT

FortisUS Inc., Color Acquisition Sub Inc., and Fortis, Inc. (collectively “Fortis”) and UNS Energy Corporation (f/k/a UniSource Energy Corporation) (the “Company”) have entered into a definitive Merger Agreement dated December 11, 2013 pursuant to which Color Acquisition Sub Inc. will merge with and into the Company, with the Company continuing as the surviving corporation (the “Merger”). As of the closing of the Merger, the Company will become an indirect wholly-owned subsidiary of Fortis, Inc. and shares of the Company’s common stock will no longer be listed on the NYSE. At Executive’s suggestion and with the consent of Fortis, in anticipation of the closing of the Merger, the Board of Directors of the Company (the “Board”) will appoint Executive to the newly created position of Executive Board Chair of the Company. At the same time, the Board also will appoint David Hutchens as the new Chief Executive Officer of the Company. As Executive Board Chair, Executive shall remain Board Chair and perform such other duties as may be assigned to him by the Board.

By signing this Amendment No. 1, Executive consents to the above-described diminution in his authority, duties and responsibilities pursuant to Section 5 of the Agreement and agrees that such diminution will not give rise to his right to receive any benefits pursuant to Section 5 of the Agreement due to a termination of employment for Good Reason as defined in Section 5(a) of the Agreement.

Section 1, Term of Agreement, is amended by adding the following paragraph to the end thereof:

Section 5, Good Reason Defined, paragraph (a) is replaced in its entirety with the following:

This Amendment No. 1 will not extinguish, limit, or impair Executive’s right to receive benefits pursuant to the Agreement for other conditions that might give rise to the payment of benefits following Executive’s appointment as Executive Board Chair, including, but not limited to, the right to receive benefits due to the termination of Executive’s employment without Cause by the Company or Executive’s termination for Good Reason due to any Good Reason event other than those described in paragraph 2 of this Amendment or in the “provided, however” clause of Section 5(a) of the Agreement, as modified by paragraph 4 of this Amendment, as long as those conditions arise while the Change in Control Agreement remains in effect.