PMI's wholly owned subsidiary is Black Sand FZE, which has a gold, precious metals and gem trading licence.
Black Sand currently has agreements for importing gold from Colombia and Honduras with a pipeline of other supply deals from other parts of South America, said the firm.
Wishbone's chairman and chief executive Richard Poulden said: "This moves Wishbone into a position where rather than being just another exploration company with promising properties it will now be in a position where it also has the support of cash flow from the trading operations in Dubai."
The initial consideration is valued at £648,000 with Wishbone issuing 240mln shares at 0.27p each.
A further payment of 240mln shares is due once the annual profit after tax of the PMI Group is more than $1mln.
Wishbone said it retained its Australian exploration properties and reckons it may be possible to realise synergies between the exploration and trading operations in the future.
Shares in Wishbone added 9.62% to 0.285p