The energy minister also defended the strength of the Brazilian system _ pointing out it took a day to fully restore power after a blackout hit the East Coast of the U.S. and Canada in 2003, leaving 50 million people in the dark. He mentioned lengthier blackouts in other nations, including Italy and Japan.
It was at least the fourth time since 1985 that Brazil has suffered a mammoth power outage blamed on transmission line failures from Itaipu.
The worst of the blackouts occurred in 1999 after lightning struck a power substation in Sao Paulo state, plunging 97 million Brazilians into darkness for up to five hours.
After severe energy shortages and rationing in 2001, Brazil diversified its energy supply. It has seen blackouts since, but none like Tuesday's failure, in which the power outage was more geographically widespread. Analysts say the scope of the blackout was so large because the nation's power grid has become more interconnected, meaning a glitch in one part can affect a wider area.
Associated Press writers Tales Azzoni in Sao Paulo, Marco Sibaja in Brasilia and John Rice in Mexico City contributed to this report.