TORONTO, May 26, 2011 /PRNewswire/ – Gran Colombia Gold Corp. (TSX: GCM) and
Medoro Resources Ltd. (TSX: MRS) (together, the “Companies“) are pleased to jointly announce that Institutional Shareholder
Services Inc. (“ISS“) is recommending that its clients vote in favour of the combination of
the Companies (the “Arrangement Resolution“), to be considered at the respective securityholder meetings of each
company scheduled for June 7, 2011.

In recommending that securityholders vote FOR the Arrangement
Resolution, ISS stated in its report*:

“The transaction is structured as a merger of equals. The companies
believe the combined company’s growth prospects are greater than either
could achieve on their own. The companies expect to realize cost
savings from a single human resources and community relations program
as well as production synergies and economies of scale from more
efficient use of facilities. The combined company will have exposure to
two large production and development projects and is expected to be
well positioned to take advantage of consolidation opportunities. The
combined management team is said to be well suited to dealing with
potential political, social and economic issues in Colombia.”

“We are pleased ISS shares our view that Gran Colombia and Medoro
securityholders should vote FOR the Arrangement Resolution,” said
Serafino Iacono, Executive Co-Chair of Gran Colombia and Interim
President and Chief Executive Officer of Medoro. “At a time of record
high gold prices, this merger enables the combined company to become
the leading Colombian-based gold production, development and
exploration company. The amalgamated companies will benefit from the
current production and expansion potential at the Gran Colombia gold
mine and the large-scale Marmato gold development project, both located
in the vicinity of Medellin, Colombia.”

A joint management information circular, dated May 6, 2011, has been
mailed to securityholders and filed on SEDAR (www.sedar.com). The joint circular contains, among other items, details regarding
the Arrangement Resolution, the terms of the acquisition, the business
of Gran Colombia and Medoro and certain historical and pro forma
financial information relating to Gran Colombia and Medoro.

ISS is a leading independent international corporate governance analysis
and proxy voting firm. Its recommendations assist securityholders in
making decisions regarding proxy voting.

Securityholders who require assistance voting their proxy should contact
Kingsdale Shareholder Services Inc., the Companies’ proxy solicitation and information agent, by: (i)
telephone toll-free in North America at 1-888-518-1563 or 416-867-2272
outside of North America; or (ii) e-mail to contactus@kingsdaleshareholder.com.

The Arrangement Resolution has received a negative recommendation from
Glass Lewis based on what the Companies believe are erroneous facts.
The Companies are in communication with Glass Lewis and are seeking
clarification and justification for the apparent inconsistencies in its
recommendations.

*Permission to quote from the ISS Report was neither sought nor
obtained.

About Gran Colombia Gold Corp.

Gran Colombia is a Canadian-based gold and silver production,
exploration and development company focused on acquiring, developing
and operating properties of merit in Colombia. Gran Colombia holds 95%
of the former Frontino Gold Mines Ltd. gold and silver assets,
including the largest underground gold and silver mining operation in
Colombia. It also owns four more exploration projects in Colombia for
total exploration acreage of approximately 21,400 hectares. Gran
Colombia is committed to implementing its exploration and development
strategy with a comprehensive environment, safety and community
program, meeting international standards of best practice.

Additional information on Gran Colombia can be found on its website at www.grancolombiagold.com and by reviewing its profile on SEDAR at www.sedar.com.

About Medoro Resources Ltd.

Medoro is a gold exploration, development and mining company with its
primary focus being the development of a large-scale, open-pit mine at
Marmato in Colombia. Medoro also has a 5% interest in the Gran Colombia
properties in Colombia with an option to increase its interest to 50%.
Medoro also holds a 100% interest in the Lo Increible 4A and 4B
concessions in Venezuela, as well as interests in gold exploration
properties in Mali.

Additional information on Medoro can be found on its website at www.medororesources.com and by reviewing its profile on SEDAR at www.sedar.com.

Cautionary Statement on Forward-looking Information

This news release contains “forward-looking information”, which may
include, but is not limited to, statements with respect to the future
financial or operating performance of Medoro, Gran Colombia and their
respective projects. Often, but not always, forward-looking statements
can be identified by the use of words such as “plans”, “expects”, “is
expected”, “budget”, “scheduled”, “estimates”, “forecasts”, “intends”,
“anticipates”, or “believes” or variations (including negative
variations) of such words and phrases, or state that certain actions,
events or results “may”, “could”, “would”, “might” or “will” be taken,
occur or be achieved. Forward-looking statements involve known and
unknown risks, uncertainties and other factors which may cause the
actual results, performance or achievements of Medoro and Gran Colombia
to be materially different from any future results, performance or
achievements expressed or implied by the forward-looking statements.
Forward-looking statements contained herein are made as of the date of
this press release based on current expectations and beliefs and Medoro
and Gran Colombia disclaim, other than as required by law, any
obligation to update any forward-looking statements whether as a result
of new information, results, future events, circumstances, or if
management’s estimates or opinions should change, or otherwise. There
can be no assurance that forward-looking statements will prove to be
accurate, as actual results and future events could differ materially
from those anticipated in such statements. Accordingly, the reader is
cautioned not to place undue reliance on forward-looking statements.

SOURCE Gran Colombia Gold Corp.