* Finance minister Mantega says to widen tax breaks
* Investment to accelerate next year - Mantega
* Inflation under control and will decline, he says
SAO PAULO, Nov 29 (Reuters) - The Brazilian government is preparing to unveil more stimulus measures to stoke an economy in which third-quarter growth is expected to be "nothing spectacular", Finance Minister Guido Mantega said in an interview published on Thursday.
"We are going to extend the PSI (a capital-goods financing program), include new sectors on the list for payroll tax breaks, and launch investment programs for the port and airport sectors," Mantega told the Folha de S.Paulo paper.
Though he would not elaborate on which sectors would be benefited by tax breaks, Mantega said that at over time they would be extended to the economy as a whole.
Mantega's comments come ahead of Brazil's official GDP data, which will be published on Friday at 9 a.m. local time (1100 GMT).
"I would be satisfied with any number between 1 percent and 1.3 percent," Mantega said, adding that a 1 percent print would indicate an annualized growth rate of 4 percent.
A Reuters poll of economists forecast a 1.2 expansion in the third quarter from the previous one.
While investments are expected to decline in the third quarter according to Reuters' poll, Mantega said, "Next year (investment) is going to be the locomotive of the economy ... growing at a rate of about 8 percent next year and 14 percent in 2014."
A barrage of government stimulus measures and steep interest rate cuts have started to slowly pull Brazil's economy out of near stagnation.
The central bank left its benchmark rate unchanged at a record low on Wednesday, however, in an effort to rein in inflation, which Mantega said was "under control and on a declining trajectory."
Press representatives at Brazil's Finance Ministry were not immediately available for comment on the report.