BRASILIA, Oct 7 (Reuters) - Brazil's annual inflation rate probably climbed further above the official target in September, a Reuters poll showed, providing fresh ammunition to opposition candidate Aecio Neves in a run-off vote against President Dilma Rousseff.
Consumer prices likely rose 6.64 percent in the 12 months through September, according to the median of 27 market forecasts for the benchmark IPCA price index.
The central bank targets inflation at 4.5 percent, with a tolerance margin of two percentage points. In August, the 12-month inflation rate stood at 6.51 percent.
Much of the September inflation pickup should come from food prices, according to economists at Credit Suisse. Meat prices in particular are expected to have risen sharply as Russia stepped up imports of Brazilian beef, chicken and pork after a recent ban on food products from other Western countries. That has tightened supplies at home and pushed up prices.
Stubbornly high inflation has been one of Brazil's biggest economic problems, denting consumer and business confidence and complicating potential government efforts to pull the economy out of recession. Inflation also eroded Rousseff's popularity ahead of her campaign for re-election. Rousseff and Neves face off in a tightly contested run-off vote later this month.
Market and government economists expect inflation to subside slightly by the end of the year, but most do not see inflation falling back to the 4.5 percent target by mid-2016, even after the central bank set interest rates at their highest in over two years, at 11 percent.
Consumer prices are expected to have risen 0.47 percent last month, compared with August and up from an increase of 0.25 percent in the prior month, according to the median forecast of 29 economists in the poll.
Forecasts for the monthly inflation rate in September ranged from 0.40 percent to 0.50 percent, while estimates for the 12-month rate varied from 6.57 percent to 6.67 percent.
National statistics agency IBGE releases the inflation numbers for September on Wednesday at 9 a.m. (1200 GMT). (Reporting by Silvio Cascione; Editing by Jeffrey Benkoe)