Segment Information

9 Months Ended

Sep. 30, 2011

Segment Information [Abstract]

Segment Information

10. Segment Information

SPS has only one reportable segment.  SPS is a wholly owned subsidiary of Xcel Energy Inc. and operates in the regulated electric utility industry providing wholesale and retail electric service in the states of Texas and New Mexico.  Revenues from external customers were $522.9 million and $467.4 million for the three months ended Sept. 30, 2011 and 2010, respectively and $1,337.4 million and $1,247.4 million for the nine months ended Sept. 30, 2011 and 2010, respectively.

Operating results from the regulated electric utility segment serve as the primary basis for the chief operating decision maker to evaluate the performance of SPS.