(Recasts with revised January data)
RIO DE JANEIRO, April 12 (Reuters) - Retail sales in Brazil started the year in much better shape than previously thought, government data showed on Wednesday, after an extraordinary upward revision for the January results offset a small drop in February.
Retail sales volumes excluding cars and building materials in Brazil fell 0.2 percent in February from January after seasonal adjustments, statistics agency IBGE said.
In January, sales rose 5.5 percent from the previous month, after being originally reported to have dropped 0.7 percent.
"The January figure was revised by a magnitude rarely seen," wrote Alberto Ramos, head of Latin America economic research at Goldman Sachs, in a report. "According to the revised figures, rather than retrenching, retail sales were booming in January."
The surprisingly good performance of Brazil's commerce in the beginning of 2017, despite record-high unemployment and double-digit interest rates, underpins hopes that the economy is about to exit its worst recession ever.
IBGE said it revised the data after changing the base year of its series to 2014 from 2011 and updating sector weightings.
Supermarket and food sales slipped 0.5 percent in February after an 8.1 percent increase in January, IBGE said. Fuel sales rose 0.6 percent in February after falling 1.3 percent in the previous month.
Sales declined 3.2 percent from the year-earlier period, compared with expectations for a 6.9 percent drop.
A broader retail sales measure that includes cars and building materials rose 1.4 percent in February from January after a 2.8 percent increase in the previous month.
Reporting by Rodrigo Viga Gaier; Writing by Silvio Cascione; Editing by Chizu Nomiyama