They told the International Olympic Committee (IOC) Executive Board here today that 67 per cent have been sold, accounting for four million out of the six million available.
This was the same figure given last week when the ticketing designs were unveiled.
"At this rhythm we are totally confident we will have a sold-out games," said the Rio 2016 director of communications Mario Andrada.
Special days have been held to roll-out high-demand tickets in popular sports such as swimming and basketball.
It follows a controversial plan where seating at some venues has been reduced as part of wholesale budget cuts.
Andrada admitted that more work remains with Paralympic sales, with only 24 per cent of tickets having been sold so far.
This is lower than the 33 per cent figure given by the International Paralympic Committee last week, but a change in the total number due to reductions for infrastructural reasons is thought to account for this.
It is hoped that sales will increase once the Olympic Games get underway.
IOC President Thomas Bach is due to travel to Rio de Janeiro later this month to inspect preparations and meet with the interim Brazilian President Michel Temer.