Following disclosure of Mr Buffett's purchase, Phibro admitted that it had been buying silver for Berkshire Hathaway.

ECONOMIST: Warren Silverfinger

Before Glencore, he worked for five years for Phibro-Salomon Inc. as a marketer, being based in New York, London and the Ivory Coast.

FORBES: Glencore Prospectus Confirms IPO Will Create Six New Billionaires

He has already been forced to sell assets he would rather have kept: Phibro, a commodities-trading firm, was ditched to assuage anger over its boss's pay packet.

ECONOMIST: Finance after the crisis

When Phibro acquired Salomon in 1981, Bloomberg was squeezed out.

FORBES: Michael Bloomberg

Citigroup (C) lost Andrew Hall, a highly profitable commodities trading talent and head of a unit known as Phibro that traded out of a Connecticut farm house, to Occidental Petroleum (OXY).

FORBES: 3 Ways Banks Will Be Killed by New Rules

Mr Buffett may have been forced to go public after a lawsuit was filed last week against Phibro, the commodities arm of the Travelers financial-services group, alleging that it was trying to manipulate the silver market.

ECONOMIST: Warren Silverfinger