BEIJING, July 15 -- China's property investment continued to soften in the first half of this year, putting the sector, once a growth engine of the economy, under greater pressure.

Real-estate investment rose 4.6 percent year on year to 4.4 trillion yuan (708.8 billion U.S. dollars) in the first half of 2015, the National Bureau of Statistics announced Wednesday.

The increase was 3.9 percentage points slower than that in the first quarter.

In the first half, investment in residential housing climbed 2.8 percent from the same period last year, slowing from 5.9 percent recorded in the first quarter.

New housing construction stood at 674.8 million square meters, plunging 15.8 percent from a year earlier, with construction on new residential houses diving 17.3 percent by area.

Sales of commercial housing went up 10 percent year on year to 3.4 trillion yuan.

China's property market took a downturn in 2014 due to weak demand and a surplus of unsold homes. The cooling has continued into 2015, with both sales and prices falling and investment slowing.

The central bank has moved to combat the slowdown, cutting benchmark interest rates and lowering banks' reserve requirement ratio.

The country also eased down payment requirements for second-home purchases at the end of March, and some local governments have rolled back their restrictions on home purchases.