BHP Billiton Canada Inc. Closes Acquisition of Athabasca Potash Inc.

Athabasca Potash Inc. ("API") announced today that BHP Billiton Canada Inc. ("BHP Billiton") completed its acquisition of all of the issued and outstanding common shares of API by way of a statutory plan of arrangement pursuant to section 186.1 of The Business Corporations Act (Saskatchewan). Pursuant to the arrangement, as set out in the Management Information Circular dated February 9, 2010, BHP Billiton acquired all of the issued and outstanding common shares of API for $8.35 cash per common share. All of the unexercised options outstanding at the time of the arrangement were cancelled for a cash payment in respect of each option equal to the amount by which $8.35 exceeded the exercise price of the option (less applicable withholding tax).

API also announced today that an application to delist API's common shares has been filed with the Toronto Stock Exchange and the delisting is expected to be effective within several trading days. An application has also been filed to allow API to cease to be a reporting issuer under applicable Canadian securities laws.