(Recasts with annual figure, adds details)
LIMA, July 15 (Reuters) - Economic growth in Peru slowed sharply to 1.22 percent on the year in May as a drop in construction sector activity outweighed expansion in the mining sector, state statistics agency Inei said on Wednesday.
The figure came in well below the 2.5 percent expansion forecast in a Reuters poll, and compared with growth of 4.25 percent in April, the fastest rate in 13 months.
A 13.56 percent contraction in the construction sector drove the slowdown in overall growth in May, as regional governments slowed down public sector works, Inei said.
The manufacturing sector also shrank by 3.46 percent.
The key mining sector, however, whose exports account for 60 percent of Peru's total, grew 8.69 percent in May on the year after expanding 18.15 percent in April.
In the 12 months through May, the economy expanded by 1.64 percent from the same period a year earlier, Inei said. Expansion so far in 2015 has been 2.14 percent.
Economic activity fell by 1.8 percent in May from April at a seasonally-adjusted rate, Inei added. (Reporting by Teresa Cespedes; Writing by Anthony Esposito and Sarah Marsh; Editing by Christian Plumb)