Brazil has said it is investigating corruption and price-fixing allegations against 18 companies, including Siemens of Germany and Alstom of France.
Other companies from Spain, Canada, South Korea and the United States, among other countries were also named.
The companies are accused of being part of a cartel to fix prices for the construction and maintenance of metro and train networks in parts of the country. The allegation cites 15 projects worth $4 billion (£2.4bn) in total.
“Several anti-competitive strategies” are alleged, including bribing dozens of officials. At times, it alleged, the cartel would also determine which company would win a bid by putting only one forward to tender an offer.
The charges are brought by the country’s Administrative Council for Economic Defence, part of the justice ministry.
Siemens said it had "zero tolerance for any kind of illegal conduct".
Alstom said it was "taking the allegations very seriously" and “carrying out its own thorough investigation”.
