Thor Mining PLC (LON:THR) shares advanced on Monday after the firm reported more positive drilling results from the Big Sandy project in Arizona, USA.

The AIM-listed group quoted a statement by Paul Lloyd, managing director of project operator Hawkstone Mining Limited (ASX:HWK), saying the final holes of a 37-hole phase 2 drilling programme had delivered “exceptional results” with high grades of lithium intercepted.

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Lloyd said these results demonstrated “significant potential” for the project to expand its resource through further drilling.

Hawkstone is targeting a maiden JORC resource for the project in September while also appointing consultants to conduct a pre-feasibility study.

Thor currently holds around 7.4mln shares in Hawkstone, equivalent to a 1% stake, but will be allotted another 7.8mln in the Australian-listed firm if it reports a mineral resource estimate for the project of at least 30mln tonnes at 2,000 parts per million of Lithium by September 2021.

“We welcome the additional positive news from the Big Sandy drilling program”, said Mick Billing, Thor’s executive chairman.

He added that the drilling program “continues to improve the prospects for Big Sandy and the value of [Thor’s] Hawkstone investment”.

Thor’s shares were 3.7% higher at 0.7p in mid-morning trading.