Silver Mines has requested a bigger upfront payment from Thomson Resources for the sale of the Webbs and Conrad silver and polymetallic projects in New South Wales.
In the previous sale agreement last month, Silver Mines only required a payment of $50,000.
Silver Mines no longer has the right to provide a nominee to the Thomson Resources board.
The company was previously planning to appoint Silver Mines managing director Anthony McClure as non-executive director of Thomson Resources.
Silver Mines is divesting the Webbs and Conrad projects, which have both enjoyed historic high-grade silver production.
A former JORC 2004 resource estimate at Webbs showed a resource of 1.5 million tonnes at 345 grams per tonne of silver for a contained 16.5 million ounces.
Conrad’s historic resource is 2.65 million tonnes at 206 grams per tonne of silver for a contained 17.5 million ounces.
Thomson Resources will also pay Silver Mines a further $269,000 and grant 70 million fully paid ordinary shares and 50 million options to the latter.
Thomson Resources must issue 35 million shares to Silver Mines upon reaching the conditions of the sale, followed by another 35 million shares six months from the agreement.
Silver Mines also owns the Bowdens silver project in New South Wales, which is the largest underdeveloped silver project in Australia.
Thomson Resources is an ASX-listed minerals explorer with a focus on silver, gold and tin in Queensland and New South Wales.