Pinnacle West Capital Corp. named Jeffrey Guldner as president of its principal subsidiary.

Guldner will be responsible for all of Arizona Public Service Co.'s affairs, except for nuclear generation, and will report to Pinnacle West Chairman, President and CEO Don Brandt. Brandt, who is also chairman and CEO of APS, will retain direct responsibility over the company's nuclear generation, which consists of the three-unit Palo Verde plant. APS operates the plant and is the largest single owner.

Most recently, Guldner served as APS' executive vice president of public policy, according to a Dec. 20 news release, and has been with the company since 2004. His prior roles also include general counsel.

James Trevathan was appointed as director of Pinnacle West and Arizona Public Service. Trevathan currently serves as executive vice president and COO at Waste Management Inc., and is retiring from that position at the end of December.