TSTR.L Regulatory News (TSTR)

TRI-STAR RESOURCES PLC

("Tri-Star" or the "Company")

Proposed Joint Venture

Exploration Licence

Letter of Intent

Tri-Star Resources PLC (AIM: TSTR) is pleased to announce that it has signed a non-binding letter of intent ("LOI") with Portage Minerals Inc (CNSX: RKX) ("Portage") under which Tri-Star will potentially fund up to CAN$12.5 million in exploration and development expenditures related to Portage's Bald Hill antimony project in New Brunswick, Canada (the "Project") in order to earn up to a 50.1% interest in the Project. Further detail on the Project is given below.

Under the terms of the LOI, Tri-Star will invest CAN$5.0 million by 31 October 2011 to earn a 15% interest in the Project. These funds will be used to fund a drilling and exploration program. Tri-Star will have the right to invest a further CAN$7.5 million in the Project within two years of the entering into the definitive joint venture agreement, in order to earn a total 50.1% interest. Portage will then have the option to fund its proportionate share of mine development costs or be diluted to a 20% carried interest. In addition, Tri-Star will be granted the right to purchase 100% of the mineral production from the Project at rates to be negotiated by the parties and Portage will be granted a 1% net smelter royalty.

There is no guarantee that the LOI, which is subject to a 30 day due diligence period and the completion of a definitive agreement by 31 August 2011, will be translated into a binding joint venture agreement (the "Joint Venture Agreement"). The Company is currently assessing a number of possible funding methods which would provide the required working capital to allow the Company to enter into the Joint Venture Agreement and further announcements will be made in due course.

Exploration Licence

In addition, the Company is pleased to announce that it has acquired an exploration block in the location of Fredericksburg in New Brunswick, Canada with a large antimony and multi element basal till anomaly which overlies the Silurian Kingsclear Group formation, which is also host to the Lake George antimony deposit and former mine, approximately 45 km to the southwest of the licence area. The property comprises of 765 claims totaling almost 17,000 Ha and covers three large basal till Sb anomalies and the area between them, a map of the property will be made available on the Company's website, www.tri-starresources.com. Further exploration work is planned during the summer, which will include basal till drilling, geophysics and stream channel geochemical analysis.

Scott Swinden PhD PGeo has been retained as a consultant on the exploration project and Don Burton MSc PGeo currently President of Namibian Rare Earths and formerly VP Exploration for Etruscan Resources, a successful gold exploration & mining company, has joined as a Director of the Company's newly formed Canadian subsidiary.

Bald Hill Antimony Project

The Project is a significant new discovery set in a geological region proven to host major antimony deposits similar to the past producing Lake George mine in New Brunswick, as well as the Beaver Brook mine in Newfoundland. The main antimony trend at Bald Hill has now been defined over 700 metres of its indicated +1.5 kilometre length and remains open in all directions. Previous results released included:

·; Potential quantity and grade of a previous drill area is in the 725,000 to 1,000,000 tonne range grading 4.11% to 5.32% Sb.

·; Initial trenching completed this year on the South Extension target returned significant antimony mineralization from a 10 metre wide sheared and altered zone containing two separate antimony (stibnite) - quartz veins up to 1.75 m in width.

·; Assay results returned 2.90% Sb over 8.18 m including 5.79% Sb over 1.75m and 8.47% Sb over 1.53 m (further detail is contained in Portage's public announcement dated 15 March 2011).

·; Another high grade antimony target located approximately 3 km east of Bald Hill on Portage's 100% owned East Property. Here, prospecting samples collected from angular boulders, assayed up to 53.00% antimony and 1.86 g/t gold. Of the eleven anomalous samples collected seven returned assay results greater than 15% Sb. The source of these high grade boulders is hypothesized to be local and thus represents an exciting exploration target for further exploration (further detail is contained in Portage's public announcement dated 10 November 2010).

Goynuk Project Turkey

As the Company announced on 20 June 2011, the Company recently appointed Spektrajeotek AS as the drill contractor for its second phase program at its Goynuk antimony project near Gediz in Turkey. The Company is currently undertaking continued exploration and evaluation of the mine area, the exploration licence area and other potential areas of interest. The Company is actively reviewing additional local sources of antimony ores to process in its plants alongside its own resource.

In addition, the Company's technical team, together with external consultants, are completing a planning and evaluation process in relation to the design and location of a concentrator for Goynuk and a new processing plant to produce antimony metal (regulus) and antimony trioxide. The Company is also reviewing other global sources of antimony concentrates to treat in the processing plant and further announcements will be made in due course.

Enquiries:

Brian Spratley, the Company's Chief Executive Officer, has relevant experience within the sector and meets the criteria of a qualified person under the AIM note for mining, oil and gas companies and has reviewed and approved the technical information contained in this announcement.