BRASILIA, Jan 21 (Reuters) - Brazil's federal tax revenues fell in 2015 to their lowest since 2010, the country's tax agency said on Thursday, highlighting the challenges the government faces to improve its finances as the economy sinks into its worst recession in decades.
Brazil's federal government collected 121.5 billion Brazilian reais ($29.25 billion) in taxes in December, down 4.32 percent from the same month a year before when discounted for inflation. For 2015, the government collected 1.221 trillion reais, down 5.62 percent from the previous year.
Economists expected December tax revenues to total 117 billion reais, according to the median forecast in a Reuters poll of 9 economists. The country collected 95 billion reais in federal taxes in November, according to the agency.
A deepening recession, Brazil's worst since 1990, has dragged down tax revenues, complicating President Dilma Rousseff's efforts to rebalance the fiscal accounts to regain the trust of investors.
Most economists doubt the government will be able to meet its 2016 primary budget surplus target equivalent to 0.5 percent of the gross domestic product. The government most likely missed its budget goal last year by a long shot as revenues plummeted.
The primary surplus, which excludes interest payments, is closely watched by investors as a measure of a country's capacity to repay its debt.
$1 = 4.1545 Brazilian reais Reporting by Alonso Soto; Editing by Chizu Nomiyama