The 55-year-old diplomat was picked over Mexico's candidate,former trade minister Herminio Blanco Mendoza, to succeed Director General Pascal Lamy of France in September, and to become the first Latin American in this post.
"During a meeting at the WTO today (Brazilian delegation members)were informed that Azevedo had collected consensus support," aministry official told dpa, adding that the WTO would formally announce the decision on Wednesday.
Brazilian President Dilma Rousseff said the election opened the path towards a new global economic order.
"This is not a victory for Brazil, or for a group of countries, but for the World Trade Organisation," Rousseff said in a statement.
"When we presented the name of Ambassador Azevedo for this high position, Brazil was convinced that, based on his experience and commitment, he could lead the organisation towards a new, moredynamic and fair economic world order. This message was understood by a significant majority," she said.
The Mexican government also congratulated Azevedo for his election.
"Mexico celebrates that, for the first time, the World Trade Organisation will be led by a Latin American," the Mexican FinanceMinistry said in a statement. "Latin America has positioned itself asa solid region with sustained growth and with broad prospects." Blanco Mendoza had already talked to Azevedo "to express his recognition and all his support in his new position," officials said.
Azevedo is a seasoned trade negotiator with a record of resolving international disputes as Brazil's ambassador to the Geneva-based organisation since 2008.
He has vowed to revive the stalled Doha Round of trade talks if appointed to lead the international trade body.
"We regard the state of paralysis in Geneva with great concern," he said in a video recorded for his campaign.
"Azevedo's election is the best hope that the Doha Round will be relaunched and that there will be a consolidation of multilateralism,instead of the several-party deals negotiated away from the WTO," former Brazilian foreign minister Luiz Felipe Lampreia told dpa.
WTO countries wanted to liberalise and expand global exports and imports through the Doha talks that started in 2001, but many countries have resorted to bilateral free-trade agreements instead as the talks have stalled.
The lack of progress is linked to the way in which the WTO takes decisions - only by consensus.
WTO trade ministers will meet in early December in Bali in an effort to break the stalemate.
Geneva diplomats have said that there might be an effort in Balito seek attainable agreements on individual topics such as customs formalities, rather than looking for a global trade framework.
"The great challenge in practice is to show that the WTO is not just the sheriff of global trade that looks after proper enforcement of already established rules," Brazilian political analyst ClovisRossi wrote in the online edition of the daily Folha de Sao Paulo.