(Adds comment from Inei chief, context on growth slowing)

LIMA, Aug 15 (Reuters) - Economic growth in Peru slowed to 3.6 percent in June from a year earlier as a drop in construction and manufacturing activity partly offset a jump in copper output, state statistics agency Inei said on Monday.

The official result for June was slightly below the 3.7 percent year-on-year expansion forecast in a Reuters poll and marked a slowdown from growth of 4.9 percent in May and 4 percent a year earlier.

Year-on-year growth slowed to 3.8 percent in the second quarter from 4.4 percent in the first quarter and 4.7 percent in the fourth quarter, Inei said.

But the annualized growth rate and the year-on-year economic expansion registered this year both came in at 4 percent in June - faster than in the same periods a year earlier.

Peru’s mining-powered economy has been recovering from a sharp slowdown in 2014, helped by soaring production from new copper mines. Domestic demand has remained relatively weak, however, and growth in recent months has come in below expectations.

“Primary activity is definitely what’s driving the economy,” Inei chief Anibal Sanchez said during a news conference.

Mining activity rose 22.3 percent year-on-year in June due to a 43.9 percent surge in copper output, Inei said. But construction shrank 3.8 percent on a drop in public investments, and manufacturing slipped 0.9 percent as fishmeal processing fell.

Sales activity rose 1.5 percent, and services for companies climbed 2.2 percent. Agriculture dropped 0.8 percent, and hydrocarbon activity fell 12.2 percent as the country’s oil pipeline remained shuttered after several leaks.

The economy shrank at a seasonally adjusted pace of 0.4 percent in June from May. (Reporting By Teresa Cespedes; Writing by Mitra Taj; Editing by Chizu Nomiyama and Lisa Von Ahn)