The opening ceremony will be held at Rio's Maracana stadium. Photo: Reuters

Seventy percent of tickets will be reserved for residents of Brazil, said the Rio Committee.

Fans can register online now, but sales will begin in March. The first results of the draw will be announced in June.

The opening ceremony for the first Olympics hosted by a South American city will be held at the Maracana stadium on 5 August 2016.

Seven-point-five million tickets will be available and more than half of them will cost $27 (£18; 70 reais) or less.

The cheapest tickets will cost $15 (£10; 40 reais)

'Fair and transparent'

Details of ticket sales for the Paralympics, which will begin on 7 September, are yet to be announced.

"We will have a fair and transparent process," said Rio 2016 Chief Commercial Officer Renato Ciuchini.

Preparations for the Rio Olympics are running behind schedule and over-budget.

But the organisers say all the venues and infrastructure projects - including a new underground line - will be ready for the Games.

The football matches are to be held in five cities - Belo Horizonte, Brasilia, Salvador and Sao Paulo, as well as Rio de Janeiro.

But last week Rio 2016 Committee President Carlos Arthur Nuzman said he was adding one or two more venues to preserve the quality of the pitches.