(Adds quarterly growth data, context)
LIMA, Nov 13 (Reuters) - Peru posted a second straight month of lower-than-expected growth as the government said on Friday the economy rose 2.95 percent in September from the same month a year ago, aided by surging copper output.
A Reuters poll had forecast a 3.3 percent expansion and the central bank and Finance Ministry had expected a rate of at least 3 percent.
The official reading marked an uptick from August's 2.57 percent year-on-year expansion, but fell short of rates that topped 3 percent in previous months. The economy grew at a seasonally adjusted rate of 0.6 percent in September from August, state statistics agency Inei said.
Growth in Peru's mining-fueled economy has slowed sharply on weaker mineral prices, but rising copper production from new mines has helped underpin official forecasts for a recovery.
Gross domestic product rose 2.9 percent in the third quarter, Inei said, down from 3.0 percent in the second quarter but up from 1.8 percent in the first.
Growth in September was led by a 44.56 percent year-on-year surge in copper production. Construction and manufacturing activity remained weak, falling by 4.87 percent and 4.2 percent, respectively, Inei said.
The unemployment rate in August through October was 5.8 percent, the lowest in 10 months.
The government has forecast a 3 percent growth rate in all of 2016, up from last year's 2.35 percent pace.
The economy expanded by 2.57 percent in the first nine months of 2015 and 2.19 percent in the past 12 months through September, from the same periods a year earlier, Inei said. (Reporting by Teresa Cespedes; Editing by Peter Cooney and Meredith Mazzilli)