Jeff Williams, Apple's senior vice president of operations, told theFinancial Times that last month was the first time it was able to verify that none of the tantalum used in capacitors and resistors in its devices had comefrom mines in conflict regions.

It is now urging "conflict-free" audits for gold, tin and tungsten suppliers by publishing a list of all its suppliers' smelters and their compliance with ethical sourcing guidelines every quarter.

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"We think it has the chance to make a difference," Mr Williams said."The smelters are a choke point where all this flows through. If we can get as many smelters verified [as possible] through this pressure, then we have a real chance of influencing the various activities on the ground."

The electronics industry faces growing criticism from human-rightsorganisations and impending regulation from US financial authorities over itsextensive use of conflict minerals mined from sites controlled by violentmilitias in the Democratic Republic of Congo and nearby areas.

"The fastest way for Apple to become conflict-free would be to channel our demand through a couple of verified smelters," Mr Williams said ahead of the publication of its annual "Supplier Responsibility" report.