MONTREAL, QUEBEC--(Marketwire - Aug. 11, 2011) - OREX EXPLORATION INC. (TSX VENTURE:OX) (FRANKFURT:O5D) and OSISKO MINING CORPORATION (TSX:OSK) (FRANKFURT: EWX) would like to provide shareholders with final assay results from the diamond drilling campaign that began in April of this year at Orex's wholly-owned Goldboro Gold Property in Nova Scotia. A total of 10 drill holes, representing 2,375.4 metres, were completed in this campaign. A total of six drill holes (OSK11-01 to OSK11-06), representing 1,610 metres of drilling, were completed at East Goldbrook. A total of four drill holes (OSK11-07 to OSK11-10), representing 765.4 metres of drilling, were completed in the gap area between West Goldbrook and Dolliver Mountain. All gold assays for this campaign have now been received. Significant gold intervals from the assays from this campaign are presented in Table 1.

The six drill holes at the East Goldbrook area were completed on three sections spaced 250 metres apart extending to the east property boundary. The holes were designed to cross-section an approximate 250- metre wide corridor identified by 2010 reverse circulation (RC) drilling to contain bedrock chip samples from six RC holes yielding grades from 0.1 to 25.65 g/t Au (refer to news release of November 18, 2010).

Results from the drilling at East Goldbrook indicate the presence of narrow high-grade gold veins often with visible gold and frequently associated with wider zones of lower-grade values extending over the 500-metre strike length to the property boundary. The mineralization is likely plunging shallowly to the east, and additional drilling will be required to further delineate the zones.

The remaining four drill holes were completed on three sections spaced 200 metres apart in the West Goldbrook – Dolliver Mountain gap, where there is no record of previous drilling. One drill hole, OSK11-07, was abandoned prior to reaching its target depth due to drilling problems. The remaining holes each intersected occasional narrow high-grade veins; however, the wall rock contains little mineralization.

Mr. Mark Billings, President and CEO of Orex, added, "The results from this campaign confirm the presence of important gold mineralization at the eastern section of our Goldboro Gold Property. There are over 500 metres of strike length that could potentially add significant upside to our current resources. In addition, we continue to find gold mineralization along the strike length of the Goldboro Gold Property, as evidenced by the results in the gap area between West Goldbrook and Dolliver Mountain. Although some of the zones are narrow, the high grades may support an eventual underground exploitation."

Hole From To Interval MS* Au gpt
metres metres metres
OSK11-01 36.00 37.00 1.00 1.82
Az 360, Dip -50, Length 247 m 86.00 88.00 2.00 1.80
128.00 130.00 2.00 0.58
OSK11-02 117.00 117.50 0.50 MS 412.00
Az 360, Dip -55, Length 286 m 117.50 128.50 11.00 0.23
174.00 191.00 17.00 0.55
including 179.50 180.00 0.50 MS 2.67
and 182.00 183.00 1.00 4.55
191.00 205.50 14.50 0.25
234.50 243.50 9.00 0.53
OSK11-03 38.00 38.95 0.95 1.28
Az 360, Dip -50, Length 251 m 46.00 50.50 4.50 1.32
88.00 91.00 3.00 0.64
143.00 143.70 0.70 4.28
OSK11-04 140.00 140.50 0.50 MS 35.10
Az 360, Dip -55, Length 299 m 193.85 194.35 0.50 MS 1570.00
194.35 197.50 3.15 0.77
204.95 224.50 19.55 0.89
including 215.00 215.50 0.50 MS 3.04
and 223.00 224.50 1.50 6.23
OSK11-05 No significant values
Az 360, Dip -55, Length 293 m
OSK11-06 40.30 42.50 2.20 0.63
Az 360, Dip -50, Length 234 m 65.15 66.70 1.55 15.80
OSK11-07 Abandoned prior to target depth
Az 180, Dip -45, Length 42.4 m
OSK11-08 89.00 92.00 3.00 0.45
Az 180, Dip -45, Length 245 m 100.00 101.50 1.50 0.64
113.00 113.50 0.50 MS 31.30
OSK11-09 68.5 70 1.50 1.75
Az 180, Dip -45, Length 240 m 83.85 84.35 0.50 MS 13.15
91.5 92.5 1.00 1.54
96.5 97.5 1.00 MS 1.28
136.5 137.7 1.20 MS 23.60
153.50 155.50 2.00 0.40
OSK11-10 62.50 65.30 2.80 0.86
Az 180, Dip -45, Length 238 m 99.00 103.50 4.50 1.13
* Metallic Screen Assay / Visible Gold

QA/QC Sampling and Analytical Protocols

The sampling and assaying of the drillcore included QA/QC protocols to monitor for potential contamination, precision and accuracy of results including the regular submission of field blank standards, certified reference standards and field duplicate split core samples. Samples were assayed using a 50 g fusion with AAS finish with sample pulps routinely re-assayed. Samples exceeding the AAS threshold were re- assayed with gravimetric finish. All samples identified to contain visible gold were assayed by the Total Metallic Screen method.

Option on Goldboro Gold Property Granted to Osisko Mining Corporation

In order to acquire a 50% undivided interest in the Goldboro Gold Property on or before September 29, 2013 (the Initial Option), Osisko Mining Corporation shall incur exploration and development expenditures in the amount of at least $1,500,000 on or before September 29, 2010; in the aggregate amount of at least $3,500,000 on or before September 29, 2011; and in the aggregate amount of at least $8,000,000 over the following two years, that is, on or before September 29, 2013. Osisko Mining Corporation may, at its sole discretion, accelerate and apply exploration and development expenditures to future years' expenditures and, accordingly, the Initial Option may be exercised sooner. Osisko Mining Corporation shall solely fund a prefeasibility study to earn an aggregate 60% interest (that is, an additional 10% interest) in the Property on or before September 29, 2015 (the Additional Option).

About Osisko Mining Corporation

Osisko Mining Corporation owns and operates the Canadian Malartic gold mine in Quebec, Canada's largest open pit gold mine. Canadian Malartic mine represents one of the biggest permitted gold reserves in Canada, and is still growing through ongoing drilling on new mineralized zones.

About Orex Exploration Inc.

Orex Exploration Inc. is a Canadian-based junior resource and exploration company trading under the symbol OX on the TSX Venture Exchange and O5D on the Frankfurt Stock Exchange. The Company holds a 100% interest in the Goldboro Gold Project in Nova Scotia.

The technical information contained in this news release has been reviewed by Mr. Bruce Mitchell, P. Geo., Senior Project Geologist to Orex, and a Qualified Person under National Instrument 43-101 regulations.

Neither the TSX Venture Exchange nor its regulation services provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release. The statements made in this news release that are not historical facts are "forward-looking statements" and readers are cautioned that any such statements are not guarantees of future performance, and that actual developments or results, may vary materially from those in these "forward-looking" statements.

Contact Information:

Osisko Mining Corporation
John Burzynski
Vice-President, Corporate Development
(514) 735-7131

Osisko Mining Corporation
Sylvie Prud'homme
Manager, Investor Relations
(514) 735-7131 / Toll-free : 1-888-674-7563

Orex Exploration Inc.
Mark Billings
President & CEO
(514) 296-1641

Frontline Communications
Leo Karabelas
(905) 553-7992