Corporate Event Notice CE10-212

Potash Corporation of Saskatchewan Inc. (“POT/POT1C”)
EXTENDED Tender Offer by BHP Billiton Development 2 (Canada) Limited
Offer Expires: November 18, 2010

Attached, for your information is an important memo from the Options Clearing Corporation.

We urge you to read this (see link) and distribute to others within your organization you deem
appropriate.

http://www.theocc.com/components/docs/market-data/infomemos/2010/sep/27719.pdf

Key Information:
Tender Offer Consideration(s) $130.00 net cash per share