In April 1959, the same year he graduated from FGV in Business Administration, he partnered with his father to create the first Pão de Açúcar supermarket store, located on Brigadeiro Luiz Antônio Avenue, in São Paulo.
In 1960, after the first store was established, Diniz traveled for four months throughout Europe and the United States to observe the operation of the retail sector abroad.
[11] In 1979, Diniz moved away from Pão de Açúcar and became part of the National Monetary Council at the urging of the Minister of Planning, Mario Henrique Simonsen.
In March 1990 the Collor government implemented an economic plan which put Pão de Açúcar on the verge of bankruptcy.
[10][12][13] In 2005, Diniz sold a large stake to the French company Casino Group for an estimated $860 million and stepped down as CEO, but remained as chairman.
[16] In 2003, Diniz became a member of the Economic and Social Development Council, a group of civil representatives which advise the President of the Republic of Brazil.
[19][20][21] In September 2013, Diniz signed an agreement with his partner Jean-Charles Naouri to leave Grupo Pão de Açúcar.
[23][24] In April 2015, Diniz announced he was wrapping up talks to raise his 5.07 percent stake in Carrefour and that he had shareholder support to take a seat on the board of the supermarket.
[30][31] In 2015, journalist Cristiane Correa wrote the book Abilio – Determinado, Ambicioso, Polêmico (Determined, Ambitious, and Controversial), released by publisher Sextante, which details his life from childhood to becoming one of the biggest businessmen of Brazil.
[32] In October 2016, Diniz launched his second book, Novos Caminhos, Novas Escolhas (New Paths, New Choices), released by publisher Objetiva (Companhia das Letras Group), which discussed the transitions in his life over the previous 12 years.
Two months after this, the audit team found no evidence that states Palocci aided the group whatsoever, giving the notion of corruption in this particular case.
Among the kidnappers were Canadians David Spencer and Christine Lamont, who were students at Simon Fraser University in British Columbia and communist activists.
The Canadian press and public started a major movement to secure their release, straining relations between Brazil and Canada.
However, two Canadian investigative journalists, Isabel Vincent of The Globe and Mail and Caroline Mallan of the Toronto Star, wrote books concluding that Lamont and Spencer were likely guilty, and they were being treated well by Brazilian authorities.
Lamont confessed to involvement in the kidnapping, which was meant to raise money for Sandinista guerrillas, and the two were released and deported to Canada in 1996.
[41] Diniz died at a São Paulo hospital on 18 February 2024, at the age of 87, after suffering respiratory failure as a result of pneumonitis.