Mario Vázquez Raña, one of the most powerful actors in the Olympic Movement in the latter part of the 20th century, has died at the age of 82.
The Mexican newspaper magnate had been ill for some time and had been unable to attend last month's General Assembly of the Pan American Sports Organization (PASO) in Puerto Vallarta on Mexico's Pacific coast.
He remained PASO President at the time of his death.
His passing is set, accordingly, to trigger a leadership election for the post he had held since 1975, with Brazil's Carlos Nuzman and José Joaquín Puello from the Dominican Republic widely seen as front runners.
In a statement on the Mexican Olympic Committee (COM) website, Carlos Padilla Becerra, COM President, described Vázquez Raña's death as "an irreparable loss".
He added: "The Olympic family in Mexico and the world is in mourning for this loss...
"A man who had the intelligence to raise American sport to its highest level has gone away."
As well as PASO, Vázquez Raña presided over the Association of National Olympic Committees (ANOC) for 33 years before resigning unexpectedly in March 2012.
He also spent 10 years from 2002 in the highly influential post of head of Olympic Solidarity, the International Olympic Committee (IOC) programme that manages the share of IOC broadcasting income, running into hundreds of millions of dollars, belonging to the National Olympic Committees and redistributes these funds via a variety of programmes.
Vázquez Raña's death comes as South America is preparing to stage its first Summer Olympic and Paralympic Games in Rio de Janeiro next year.
The PASO region will also host both the 2018 Youth Olympic Games in Buenos Aires and the IOC Session at which the host of the 2024 Olympics and Paralympics will be selected in Lima in 2017.