SÃO PAULO, Brazil — In a disappointment for Boeing, Brazilian defense officials said on Wednesday that they had picked the aircraft maker Saab for a $4.5 billion contract to build 36 fighter jets over the next 10 years.

The Brazilian defense minister, Celso Amorim, told reporters at a news conference in Brasilia that Saab was selected over Boeing because it had agreed to share more technology with contractors and because many parts for the new jet, the Gripen NG, would be made in Brazil.

The decision “took into account performance, the effective transfer of technology and costs, not only of acquisition, but also of maintenance,” Mr. Amorim said in a statement. He was accompanied by Gen. Juniti Saito, the Brazilian air force’s chief of staff. “The decision was based on these three factors.”

The announcement comes at a time of heightened tension between the United States and Brazil. In September, the Brazilian president, Dilma Rousseff, canceled a state visit to the United States after revelations that the National Security Agency was spying on foreign heads of state, including her.