DIRCE Navarro de Camargo, Brazil's richest woman and the widow of the founder of the private conglomerate Camargo Correa, has died at the age of 100, press reports say.

The daily Folha de Sao Paulo said Camargo died at her home on Saturday.

According to Forbes magazine, she was the fourth richest person in Brazil and the country's wealthiest woman with a net worth estimated at $US11.5 billion ($A11.24 billion).

Camargo controlled Camargo Correa, the group founded by her late husband Sebastiao Camargo, with her three daughters, Regina, Renata and Rosana.

The Sao Paulo-based conglomerate has wide-ranging business interests, including in cement, real estate, construction and energy.

The group also controls the footwear company Alpargatas, the Brazilian maker of the famous Havaianas flip-flops.