WASHINGTON — A federal judge on July 24 upheld a U.S. Securities and Exchange Commission rule that will require about 6,000 publicly traded companies to report whether their products contain four so-called conflict minerals from the Democratic Republic of the Congo, where warlords use proceeds from the mineral sales to finance murder, rape and torture.

The National Association of Manufact­urers, the U.S. Chamber of Commerce and the Business Roundtable sued the SEC to block the rule, which they said might cost as much as $16 billion to implement.