Brazzilmag.
An inflated stock price based mostly on hype about enormous pre-salt oil fields has raised Petrobras' value.
"According to figures supplied by Economática, Petrobras' market value has gone from US$ 95.84 billion, as of December 31st, 2008, to US$ 173.59 billion, as of August 4.
The company was surpassed only by the American companies ExxonMobil (US$ 344.5 billion), Microsoft (US$ 211.8 billion) and Wal Mart (US$ 196.2 billion).
Last year, Petrobras ranked 17th in the list, which does not include Canadian companies."