(Adds details on employment, wages, background)
RIO DE JANEIRO, Feb 26 (Reuters) - Brazil's jobless rate rose from an all-time low to the highest in more than one year in January, flagging the recessionary risks of a government austerity drive which has raised taxes and reined in spending.
Brazil's non-seasonally adjusted jobless rate rose more than expected in January to 5.3 percent, the highest since September 2013, from 4.3 percent in December, statistics agency IBGE said. The median forecast in a Reuters poll of 25 economists was 5.0 percent.
Mounting job losses could pile political pressure on President Dilma Rousseff, already weakened by a massive corruption scandal at state-run oil company Petroleo Brasileiro SA and by unpopular austerity measures.
Brazil has scrambled to raise taxes and freeze spending after ratings agencies warned it could lose investment-grade status. Although investors have welcomed the belt-tightening, it has also hurt an already weak economy, raising the prospect of a recession in 2015.
Market economists expect Brazil's economy to shrink 0.5 percent in 2015, in its weakest performance since 1992, according to a weekly central bank poll.
A separate government survey expected to be released later this week is forecast to show Brazilian companies shed jobs for a second straight month in January, the worst start to a year since 2009.
The IBGE report showed the number of Brazilians with jobs in the six major metropolitan areas surveyed fell 0.9 percent from December, to 23.0 million. The tally of people who unsuccessfully looked for work increased 22.5 percent from December, to 1.3 million.
Real wages, or salaries discounted for inflation, rose 0.4 percent from December to an average of 2,168.80 reais ($763) a month. That was 1.7 percent higher than a year earlier.
The unemployment rate, as calculated by the IBGE, tallies jobs in the formal sector, where employees are legally registered, as well as off-the-books jobs.
$1 = 2.843 Brazilian reais Reporting by Rodrigo Viga Gaier; Writing by Silvio Cascione Editing by W Simon