(Recasts story with revised amount set to be frozen)

BRASILIA, March 20 (Reuters) - Brazil's government will freeze 2.9 billion reais ($583.9 million) in expenses on Friday in order to meet fiscal rules this year, according to two sources from the government.

Brazilian President Luiz Inacio Lula da Silva told several of his ministers the amount in a meeting on Wednesday, the sources said.

The government will announce the freeze on Friday in its bi-monthly revenue and spending report, a document which assesses public accounts' performance to date and provides projections for the year.

Before the meeting led by Lula, sources told Reuters the most recent calculations had been leaning toward a freeze of about 5 billion reais, cautioning that changes could be made to the number through Friday.

The move is necessary to offset higher-than-expected mandatory spending, said the sources.

"Revenue is expected to perform well, with some positive and negative surprises balancing each other out. Revenue will make the difference as the market is not believing in it," one of the sources said.

According to one of the sources, the report is expected to show a 2024 primary deficit below 10 billion reais, which would be within the tolerance margin this year.

The fiscal target aims for a zero deficit in 2024, with a tolerance band of 0.25% of gross domestic product (GDP), equivalent to about 29 billion reais.

Private economists surveyed weekly by the central bank forecast a primary deficit of 0.75% of GDP this year.

While a positive revenue performance may ease pressures for a fiscal target change, spending touches a sensitive point for leftist President Lula, who advocates for increased public investments.

Earlier this month, Lula said the government would eventually need to discuss with Congress a change in the country's "spending limit" to provide more benefits to the population. ($1 = 4.9663 reais) (Reporting by Bernardo Caram and Lisandra Paraguassu, Editing by Franklin Paul and Lincoln Feast.)