South American Silver is seeking US$385.7 million in compensation or a return of the project and US$176.4 million.
TriMetal is headquartered in Vancouver and listed on the Toronto Stock Exchange. Its shares closed Wednesday at 17.5 cents, giving it a total market value of about $23.7 million.
Prior to the expropriation in July 2012, TriMetals traded above $1 a share.
South American Silver is registered in Bermuda and comes under U.K. jurisdiction. The claim was filed Wednesday in The Hague, at the Permanent Court of Arbitration. The arbitration is brought under the UK-Bolivia Bilateral Investment Treaty.
"We are satisfied to see that the arbitration is moving forward in pursuit of full compensation for South American Silver who suffered significant losses as a result of Bolivia's blatant and deliberate breaches of the treaty and international law," Ralph Fitch, TriMetals CEO and chairman, said in a statement on Thursday.
TriMetals is a mineral exploration company with a gold-silver project in the U.S. states of Nevada and Utah and a copper-gold project in Chile.