Koulékoun Resource Increases By 34% To 1.47m Ozs

AVOCET MINING PLC

KOULÉKOUN, GUINEA GOLD RESOURCE INCREASESBY 34% TO 1.47 MILLION OUNCES

Avocet Mining PLC ("Avocet" or "the Company") announces an updated Mineral Resource of 1.47 million ounces at Koulékoun in the 100 per cent owned Tri-K block of permits in northeast Guinea. This is an increase of 376,100 ounces or 34 per cent overthe Mineral Resource published in May 2011 at the same cut-off of 0.5g/t Au.

The table below reports the revised Mineral Resource in accordance with the Australian JORC Code. The Mineral Resource has been estimated in accordance with the principle of the Canadian NI 43-101 and Australian JORC code.

Note: CSA Global estimated the updated Mineral Resource using ordinary kriging and validated by inverse distance squared interpolation. All estimates are constrained by geologically controlled wire frames. Gold grades utilised a top cut of 50 g/t Au in the porphyry and wall rock mineralisation and 20 g/t Au along the northeast-striking structure. Rounding errors may exist.

As reported in May 2011, a 40-80m thick, steeply east-dipping zone of north-northwest-striking porphyry dykes, cut by a steeply north-dipping northeast-striking structure, hosts the Koulékoun Mineral Resource. To date, these structures have been tested over a strike length of 2,000 metres and a vertical depth of 350 metres (Figure 1).

Drilling has historically been oriented east-west to intersect the mineralised porphyry dykes, which are the main host to gold mineralisation. However, recent drilling has intersected significant mineralisation in the northeast-striking structure. The historic direction of drilling has therefore resulted in conservative constraints on the extent of the Mineral Resource, an increase in the proportion of Inferred Mineral Resources and a reduced average gold grade. Optimised drilling toward the southeast in the fourth quarter will allow the more accurate estimate of the Mineral Resources in this zone.

The updated Mineral Resource is based on data as at 18 August 2011 from 347 reverse circulation ("RC") drill holes (34,034m) and 108 diamond ("RD" and "DD") drill holes (26,330m), which includes an additional 28 RC drill holes (3,353m) and 24 RD drill holes (6,143m) completed since the last Mineral Resource update on 11 May 2011.

Table 1 lists the significant intercepts from the new drill holes included in the updated Mineral Resource, which include the following highlights:

·; 68 m @ 2.99 g/t Au from 132 m in KLRD0018

·; 55 m @ 2.85 g/t Au from 408 m in KLRD0012 (incl. 26m @ 4.67 g/t Au and 2m@ 2.30 g/t Au)

·; 53 m @ 1.89 g/t Au from 66 m in KLRD0032 (incl. 2m @ 4.81 g/t Au and 4m

@ 3.94 g/t Au)

·; 49 m @ 1.92 g/t Au from 405 m in KLRD0017

·; 31 m @ 2.66 g/t Au from 71 m in KLRD0033 (incl. 22m @ 3.38 g/t Au)

Assays from an additional 23 RC drill holes, one RD drill hole and four DD holes are yet to be received. These will be included, together with the results of the upcoming Q4 drilling programme, in a further updated Mineral Resource to be announced before the year end. This resource update is expected support the Company's intention to progress the project to a definitive feasibility study in 2012.

Commenting on the Mineral Resource upgrade at Koulékoun, Brett Richards, Chief Executive Officer for Avocet, said:

"The updated Mineral Resource at Koulékoun is in line with our expectations and shows that we are on track to achieve our goal of defining two million ounces in the Tri-K region from the 2011 drilling programmes. These encouraging results have underpinned our commitment to continue with another field season of infill drilling within the Tri-K region, in an effort to grow the resource base beyond current levels. Our West African Mineral Resources have now more than doubled to 5.40 million ounces gold since our acquisition of these assets in 2009, with further growth potential still to be realised."

The information in this announcement that relates to Exploration Results is based on information reviewed and audited by Mr Peter Flindell, (MAusIMM), Executive Vice President of Exploration for Avocet, and the information in this announcement that relates to Mineral Resources is based on information compiled by Mr David Williams(MAusIMM, MAIG), Principal Consultant, CSA. Mr Williams has the experience relevant to the style of mineralisation and type of deposit under consideration to qualify as a Qualified Person as defined by the Canadian National Instrument 43-101 for the reporting of Exploration Results, Mineral Resources and Mineral Reserves (NI 43-101) and Mr Flindell and Mr Williams are Competent Persons as defined by the Australasian JORC Code (2004) for the reporting of Exploration Results, Mineral Resources and Ore Reserves. Mr Williams and Mr Flindell consent to the inclusion of the technical information in this announcement in the form and context in which it appears.

Notes to Editors

Avocet Mining PLC ("Avocet" or "the Company") is a gold mining and exploration company listed on the AIM market of the London Stock Exchange (Ticker: AVM.L) and the Oslo Børs (Ticker: AVM.OL). The Company's principal activities are gold mining and exploration in Burkina Faso (as 90 per cent owner of the Inata gold mine and 100 per cent owner of eight exploration licences in the Bélahouro region surrounding Inata) and exploration in Guinea.

In December 2010 Avocet announced that it had signed a binding agreement for the conditional sale of its South East Asian assets to J & Partners L.P., a private company, for US$200 million. To date US$197 million of the total consideration has been received.

The substantial completion of this transaction has left Avocet as a West African gold producer and explorer, with a clear strategy for growth in that region.

The Inata deposit presently comprises a Mineral Resource of 3.36 million ounces and a Mineral Reserve of 1.46 million ounces. Inata poured its first gold in December 2009. Other assets in West Africa include exploration permits in Burkina Faso (the most advanced prospect within Bélahouro being the Souma trend, some 20 kilometres from Inata, with a Mineral Resource of 561,100 ounces), Guinea (the most advanced being Koulékoun with a Mineral Resource of 1.5 million ounces) and Mali.

FIGURE 1: LOCATION OF SIGNIFICANT INTERCEPTS AT KOULEKOUN

http://www.rns-pdf.londonstockexchange.com/rns/0026R_-2011-10-27.pdf

TABLE 1: KOULEKOUN NEW SIGNIFICANT INTERCEPTS