The National Security Agency (NSA) has tapped into the networks of Google, Brazilian oil firm Petroleo Brasileiro SA, and systems operated by France's foreign ministry, according to leaked US documents.
The documents were aired by Brazil's biggest television network, Globo, a week after it reported that the NSA had spied on the presidents of Brazil and Mexico.
Globo co-ordinated its exposé with more revelations from Guardian journalist Glenn Greenwald, who has worked in tandem with former CIA and NSA employee Edward Snowden to bring to light the extent of the US's spying at home and abroad.
Greenwald claimed that the documents he obtained from Snowden contain "much more information on spying on innocents, against people who have nothing to do with terrorism, or industrial issues, which need to be made public".
The Brazilian broadcast involved slides from an NSA presentation dated May 2012 that Globo said were used to show new NSA employees how to spy on private computer networks.
As well as the networks of Google, Petroleo Brasileiro and the systems operated by France's foreign ministry, the slides suggested that the NSA had tapped into the Society for Worldwide Interbank Financial Telecommunication (Swift) - an international bank cooperative that handles many global financial transactions.
James Clapper, the US director of national intelligence, admitted that US government agencies collect information about economic and financial matters but suggested that the data is used to prevent terrorist financing and predict issues that could culminate in a financial crisis.
"What we do not do, is use our foreign intelligence capabilities to steal the trade secrets of foreign companies on behalf of - or give intelligence we collect to - US companies to enhance their international competitiveness or increase their bottom line," Clapper said in a statement.
The latest revelations are likely to further strain relations between Brazil and the US, after the NSA was alleged to have spied on the phone calls and emails of Brazil's president, Dilma Rousseff.
Brazilian authorities have reportedly demanded a formal apology, and Rousseff met with US president Barack Obama last week at the G20 meeting in Russia, where he said he would investigate the allegations.