BRASILIA, July 31 (Reuters) - Brazil posted a primary budget deficit of 9.323 billion reais ($2.78 billion) in June, central bank data showed on Friday, above market expectations.

The primary budget had been expected to show a deficit of 2 billion reais in June, according to the median forecast of 15 analysts surveyed by Reuters.

($1 = 3.35 Brazilian reais) (Reporting by Alonso Soto and Marcela Ayres; Writing by Silvio Cascione; Editing by Chizu Nomiyama)