BRASILIA, Sept 22 (Reuters) - Brazil’s government forecast a smaller primary budget deficit this year due to rising revenues from the economic rebound from the coronavirus pandemic, the Economy Ministry’s bi-monthly revenue and expenditure report said on Wednesday. The 2021 primary deficit is estimated now at 139.4 billion reais ($26.4 billion), down from 155.4 billion reais forecast in July, equivalent to 1.6% of gross domestic product compared to 1.8% previously expected. Net revenue is forecast at 1.508 trillion reais, up from 1.4876 trillion reais, and primary spending is seen at 1.647 trillion reais, up from 1.632 trillion reais in July forecast.