PSI Files Merger-Related Petition In Indiana

PLAINFIELD, Ind., June 15, 2005 — PSI Energy Inc., the Indiana public utility subsidiary of Cinergy Corp. (NYSE:CIN), today filed a petition with the Indiana Utility Regulatory Commission supporting the proposed merger of Cinergy and Duke Energy (NYSE:DUK).

In the petition, PSI emphasized the transaction will create a financially stronger organization that will continue PSI’s long record of reliable electric service to its customers at reasonable rates. The combined company will maintain a strong local presence in Indiana with continuing support of economic development and philanthropic activities in its Indiana service area.

“With this merger, we are becoming part of a company that, along with Cinergy, is known for excellence in customer service,” said PSI President Kay Pashos. “We share similar values and operating philosophies, and our longstanding commitment to community giving and involvement will be enhanced by the combination of two civic-minded companies backed by a financially stronger organization.”

PSI will remain a separate and distinct Indiana utility company after the merger. The merger will have no effect on the regulation of electric utility service by the Indiana Utility Regulatory Commission, and PSI’s customer rates will continue to be set by the state commission. PSI Energy’s corporate headquarters will remain in Plainfield, Ind., with staffing, experience and resources in Indiana necessary to maintain high-quality customer service and reliable delivery of electricity.

“In the years after the transaction is completed, the efficiencies and economies of scale from the larger company will provide significant long-term benefits to both customers and shareholders,” Pashos said. In its petition PSI commits to share a portion of the merger savings that are allocable to PSI’s electric operations with its Indiana customers.

This is among several regulatory filings regarding the merger that will be made in the next several weeks and months at the state and federal level.

PSI Energy is Indiana’s largest electric supplier, serving more than 700,000 customers in portions of 69 of the state’s 92 counties.

Forward-Looking Statement
This document includes statements that do not directly or exclusively relate to historical facts. Such statements are “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. These forward-looking statements include statements regarding benefits of the proposed mergers and Restructuring Transactions, integration plans and expected synergies, anticipated future financial operating performance and results, including estimates of growth. These statements are based on the current expectations of management of Duke Energy and Cinergy. There are a number of risks and uncertainties that could cause actual results to differ materially from the forward-looking statements included in this document. For example, (1) the companies may be unable to obtain shareholder approvals required for the transaction; (2) the companies may be unable to obtain regulatory approvals required for the transaction, or required regulatory approvals may delay the transaction or result in the imposition of conditions that could have a material adverse effect on the combined company or cause the companies to abandon the transaction; (3) conditions to the closing of the mergers and the restructuring transactions may not be satisfied; (4) problems may arise in successfully integrating the businesses of the companies, which may result in the combined company not operating as effectively and efficiently as expected; (5) the combined company may be unable to achieve cost-cutting synergies or it may take longer than expected to achieve those synergies; (6) the transaction may involve unexpected costs or unexpected liabilities, or the effects of purchase accounting may be different from the companies’ expectations; (7) the credit ratings of the combined company or its subsidiaries may be different from what the companies expect; (8) the businesses of the companies may suffer as a result of uncertainty surrounding the transaction; (9) the industry may be subject to future regulatory or legislative actions that could adversely affect the companies; and (10) the companies may be adversely affected by other economic, business, and/or competitive factors. Additional factors that may affect the future results of Duke Energy and Cinergy are set forth in their respective filings with the Securities and Exchange Commission ("SEC"), which are available at www.duke- energy.com/investors and www.cinergy.com/investors, respectively. Duke Energy and Cinergy undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

Additional Information and Where to Find It
In connection with the proposed transaction, a registration statement of Deer Holding Corp., which will include a joint proxy statement of Duke Energy and Cinergy, and other materials, will be filed with SEC. WE URGE INVESTORS TO READ THE REGISTRATION STATEMENT AND PROXY STATEMENT AND THESE OTHER MATERIALS CAREFULLY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT DUKE ENERGY, CINERGY, DEER HOLDING CORP., AND THE PROPOSED TRANSACTION. Investors will be able to obtain free copies of the registration statement and proxy statement (when available) as well as other filed documents containing information about Duke Energy and Cinergy at http://www.sec.gov, SEC's Web site. Free copies of Duke Energy’s SEC filings are also available on Duke Energy’s Web site at www.duke-energy.com/investors and free copies of Cinergy’s SEC filings are also available on Cinergy’s Web site at www.cinergy.com/investors.

Participants in the Solicitation
Duke Energy, Cinergy and their respective executive officers and directors may be deemed, under SEC rules, to be participants in the solicitation of proxies from Duke Energy’s or Cinergy’s stockholders with respect to the proposed transaction. Information regarding the officers and directors of Duke Energy is included in its definitive proxy statement for its 2005 annual meeting filed with SEC on March 31, 2005. Information regarding the officers and directors of Cinergy is included in its definitive proxy statement for its 2005 annual meeting filed with SEC on March 28, 2005. More detailed information regarding the identity of potential participants, and their direct or indirect interests, by securities, holdings or otherwise, will be set forth in the registration statement and proxy statement and other materials to be filed with SEC in connection with the proposed transaction.