BRASILIA, Sept 17 (Reuters) - Brazil's government is committed to lowering the country's tax burden as a share of its gross domestic product, but not necessarily in absolute terms, Productivity and Competition Secretary Carlos da Costa said on Thursday.

Speaking in a live event hosted by online media outlet Poder 360, da Costa said taxes would not be allowed to rise as fast as the rate of GDP growth, and added that the government wants to end specific payroll tax exemptions and lower the burden for all taxpayers. (Reporting by Marcela Ayres and Jamie McGeever; Editing by Sandra Maler)