|Jobim's most significant disagreement with Rousseff was over a multi-billion-dollar fighter-plane deal [Reuters]
Dilma Rousseff, the Brazilian president, has replaced her country's defence minister after he made disparaging remarks about fellow officials.
Nelson Jobim, a veteran politician, tendered his resignation during a brief meeting with Rousseff on Thursday, and will be replaced by Celso Amorim, a former foreign minister.
Jobim, 69, is the third minister to have lost his place in Rousseff's cabinet after either clashing with her or facing corruption allegations.
The resignations has strained relations between members of her 15-party coalition government and has also led to the stalling of economic reforms in the country's parliament.
Jobim, one of several officials who also served under Luiz Inacio Lula da Silva, Rousseff's predecessor, was reportedly unhappy in his job virtually from the moment he agreed to continue on after Lula da Silva's term was up.
In recent weeks, he had become openly insubordinate, saying in a TV interview that he had voted for Jose Serra, Rousseff's opponent, in last year's presidential election.
He had also raised eyebrows when, at an opposition party event in Brasilia, the capital, he said he was surrounded by "idiots".
The last straw appears to have been a magazine interview, parts of which were leaked on Thursday, in which Jobim called Ideli Salvatti, the minister of institutional relations, a "little weakling".
He also said that Gleisi Hoffman, who took the job of chief of staff in June, "doesn't even know Brasilia", the Folha de S.Paulo newspaper reported.
Jobim has denied that he criticised Hoffman, and said the report was part of a campaign against him.
Defence deal row
Officials told the Reuters news agency that Jobim was angry at having been overruled on a major defence deal early in Rousseff's term, when she had decided to restart the bidding process for a multi-billion-dollar air force fighter-plane contract.
Jobim favoured French firm Dassault's Rafale, while Rousseff has said that she thinks Boeing's F/A-18 is the best choice.
Rousseff has won praise for her handling of the Brazilian economy since taking over office on January 1.
However, she has been criticised for her micromanaging of policy and for her attitude towards subordinates.
Jobim's centrist PMDB party has constantly fought with the president and her Workers' Party over issues ranging from budget cuts to political appointments.
Amorim at policy forefront
As the country's top diplomat from 2003 to 2010, Amorim was at the forefront of implementing an assertive foreign policy of engaging with other developing countries, and putting Brazil in a critical leadership position in global talks on trade and the environment.
At the time, he was considered to be one of the world's most influential foreign ministers.
Rousseff's transport minister resigned last month after corruption allegations were levelled against him.
Antonio Palocci, a top Rousseff aide, also quit in June amid questions over a large rise in his personal wealth.