May 08, 2013

Bernstein Liebhard LLP is investigating whether the Board of Directors of Pioneer Southwest Energy Partners L.P. (“Pioneer Southwest” or the “Company”) (NYSE: PSE) is breaching its fiduciary duty to its shareholders in connection with a proposed transaction to sell Pioneer Southwest to Pioneer Natural Resources Company (“Pioneer”) (NYSE: PXD), the majority shareholder of Pioneer Southwest.

Subject to negotiation and execution of a definitive agreement, Pioneer is proposing consideration of 0.2234 of a share of Pioneer common stock for each outstanding publicly-held Pioneer Southwest common unit Pioneer does not already own.  Pioneer owns 100% percent of the general partner of Pioneer Southwest and owns approximately 52.4% of the 35,713,700 outstanding common units of Pioneer Southwest.  The investigation is focused on the potential unfairness of the price to Pioneer Southwest shareholders and the process for consideration of the proposed transaction by the Pioneer Southwest Board of Directors.

If you are interested in discussing your rights as a Pioneer Southwest stockholder, with no obligation or cost to you, please contact Joseph R. Seidman, Jr. at (877) 779-1414 or seidman@bernlieb.com.

Bernstein Liebhard LLP has pursued hundreds of securities, consumer and shareholder rights cases and recovered over $3 billion for its clients.  It has been named to The National Law Journal’s “Plaintiffs’ Hot List” in each of the last ten years.