By Jeffrey T. Lewis

SAO PAULO--Brazil's inflation accelerated in September as the country's weak currency boosted exports of food, pushing prices higher and raising the possibility the country's central bank will raise rates sooner than expected.

Consumer prices increased 0.64% from August, the Brazilian Institute of Geography and Statistics, or IBGE, said Friday. Prices rose 3.14% from a year earlier. In August, prices rose 0.24% and increased 2.44% from a year earlier.

The September figure pushed Brazil's 12-month inflation rate into the central bank's target range of 2.5% to 5.5% and closer to the 4% central point of the range, after spending months beneath the lower limit.

The slow price increases since the start of the coronavirus pandemic have allowed the bank to cut its benchmark lending rate to a record low of 2%, and the bank said at its last meeting that it won't reduce monetary stimulus unless inflation starts to heat up.

But with the faster-than-expected rise in prices in September, and the outlook for more pressure on food prices in coming months, the central bank might have to start thinking about raising its benchmark Selic lending rate, according to economists. The bank also has expressed concern about the government's fiscal situation, which has gotten worse amid increased spending to ease the impact of the coronavirus pandemic.

"The data show relevant pressure in the short term on consumer prices, and that could test the central bank's patience," said Andre Perfeito, chief economist at the Necton brokerage in Sao Paulo. "We're very probably going to have an increase in the Selic" before previously expected.

The Brazilian real has lost more than a quarter of its value against the dollar since the start of this year, making its agricultural output cheaper for foreign buyers.

Poorer Brazilians also have been spending more because of the aid payments the government is making to help people who have lost work because of the pandemic, according to Pedro Kislanov, the research director for the IBGE's inflation series.

"When more is exported, it reduces supply to the domestic market," he said.

Food price leapt 2.28% in September from August, after an increase of 0.78% in August, with the cost of staples soaring. The price of rice rose 17.98% in the month, and the cost of soy oil increased 27.5% from August, the IBGE said.

Write to Jeffrey T. Lewis at jeffrey.lewis@wsj.com

(END) Dow Jones Newswires

10-09-20 0903ET