FIFA said 588,178 tickets had already been bought for the eight-nation tournament which features the champions from each confederation as well as hosts Brazil, Italy and Uruguay and acts as a rehearsal for next year's World Cup.
"Due to delayed stadium deliveries, we are only now in the position to conduct the seat allocations in each of the venues," FIFA's marketing director Thierry Weil said in a statement.
"Yet we are very confident that we will break another record for the FIFA Confederations Cup, with the Brazilians providing the global TV audience with a glimpse of what kind of stadium atmosphere to expect in 2014."
Some 58,000 tickets have been sold for Brazil's opening match against Japan in Brasilia and 60,000 have already gone for the final, but Tahiti versus Nigeria in Belo Horizonte is proving less of a draw with only 10,000 snapped up so far.
FIFA said 97 percent of the tickets sold so far had been purchased by Brazilians.
The 16 matches at the 2009 Confederations Cup in South Africa were watched by 584,000 fans - an average of 36,555.
- Sports & Recreation