BRASILIA, Oct 31 (Reuters) - Brazil posted a primary budget deficit of 25.491 billion reais ($10.4 billion) in September, central bank data showed on Friday, a gap well above market expectations.
The primary budget had been expected to show a deficit of 12.25 billion reais in September, according to the median forecast of 10 analysts surveyed by Reuters.
In the first nine months of the year, a primary surplus has turned into a deficit of 15.286 billion reais after five straight monthly deficits.
The government is aiming for a primary surplus, which represents the public sector's excess revenue over expenditures before debt payments, of 99 billion reais or the equivalent of 1.9 percent of gross domestic product for full-year 2014.
The country posted a primary deficit of 14.46 billion reais in August. ($1 = 2.4474 Brazilian reais) (Reporting by Alonso Soto and Anthony Boadle; Editing by James Dalgleish)