TORONTO, Dec. 4, 2012 /PRNewswire/ – Compania Minera Auromin Ltda.
(“Auromin”), a company controlled by David Thomson, a director and
officer of Cerro Grande Mining Corporation (the “Company”), announces
that it has acquired one convertible debenture (the “Debenture”) in the
aggregate principal amount of US$863,980 (CDN$863,980) (the
“Principal”) from the Company, which is convertible into up to
2,879,933 Common Shares of Cerro Grande Mining Corporation (each, a
“Common Share”) assuming full conversion of the Principal into Common
Shares. The Debenture was issued in full satisfaction for a cash
advance made to the Company by Auromin.

Prior to the acquisition, David Thomson beneficially owned, and/or
exercised control or direction over, directly or indirectly, 14,805,506
Common Shares and 650,000 stock options to acquire 650,000 Common
Shares of the Company (the “Options”), representing 15.59% of the
outstanding Common Shares, assuming the exercise of the Options.
Assuming the full conversion of the Principal into Common Shares under
the Debenture, Mr. Thomson would beneficially own, and/or exercise
control or direction over, directly or indirectly, 17,686,089 Common
Shares representing 18.08% of the outstanding Common Shares on a
partially diluted basis.

Mr. Thomson may in the future increase or decrease his ownership of
securities of the Company from time to time depending upon the business
and prospects of the Company and future market conditions.

Minera’s address is Avda. Santa Maria 2224, Providencia, Santiago,
Chile.

SOURCE COMPANIA MINERA AUROMIN LTDA.