RIO DE JANEIRO, Dec. 28 (Xinhua) -- Brazil's Presidential Chief of Staff Dilma Rousseff said on Thursday that renovations in the country's aviation sector will help prevent the chaos that occurred at airports on the Christmas weekend.

    Rousseff said that the sector was a monopoly until when the airline Varig went bankrupt and was split into two smaller companies earlier this year.

    In any sector there has to be regulation and it is necessary to have clear rules. But up until very recently, the aviation sector was a monopolist one, said Rousseff.

    She said that when passengers who do not show up are punished and airlines that overbook flights are fined in some countries.

    Brazil's air traffic crisis was aggravated on Tuesday when at least 120 flights were delayed in Sao Paulo's airport due to the slowdown operation by staff members of the Air Traffic Control Center (Cindacta 1) in the country's capital city of Brasilia.

    Since the beginning of the slowdown on Dec, 27, passengers had to wait 30 to 40 minutes inside airplanes until they got the permission to take off, and flights got delayed up to 3 hours.

    At Congonhas airport, close to downtown Sao Paulo, Brazil's largest city, 79 flights were behind schedule on Tuesday.