Former Attorney General of Louisiana, Charles C. Foti, Jr., Esq., and the law firm of Kahn Swick & Foti, LLC ("KSF") announce that KSF has commenced an investigation into the Board of Directors of Pioneer Southwest Energy Partners L.P. ("Pioneer Southwest" or the "Company") (NYSE: PSE) in connection with their conduct related to the proposed sale of the Company to Pioneer Natural Resources Company (NYSE: PXD). Under the terms of the proposed transaction, shareholders of Pioneer Southwest will receive 0.2325 shares of Pioneer for each share of Pioneer Southwest common stock that they own.

KSF's investigation is focusing on whether Pioneer Southwest and/or its officers and directors secured sufficient value for the shareholders of the Company, violated their fiduciary duties, and/or violated state or federal securities laws.

If you have information that would assist KSF in its investigation, or would like to discuss your legal rights, you may, without obligation or cost to you, e-mail or call KSF Managing Partner Lewis S. Kahn (lewis.kahn@ksfcounsel.com) or attorney Michael Palestina (michael.palestina@ksfcounsel.com) toll free at 855-768-1857 or via cell phone any time at 504-236-7315.

About Kahn Swick & Foti, LLC

KSF, whose partners include the Former Louisiana Attorney General Charles C. Foti, Jr., is a law firm focused on transactional litigation, as well as securities class action and shareholder derivative litigation. With offices in New York and Louisiana, KSF's lawyers have significant experience litigating complex securities class actions nationwide on behalf of both institutional and individual shareholders.

To learn more about KSF, you may visit www.ksfcounsel.com.

Kahn Swick & Foti, LLC
Michael Palestina, Esq., 855-768-1857
or after hours via cell phone 504-236-7315
michael.palestina@ksfcounsel.com