China's building materials sector recorded slower growth in the first four months of this year as a cooling housing market has dashed hopes for lasting rapid expansion, according to the latest statistics from the country's top economic planner.

Cement output grew a mere 4.3 percent from a year ago to 672 million tonnes in the January-April period, slowing 4.2 percentage points from last year's growth, according to industrial reports by the National Development and Reform Commission (NDRC) on its website.

While China's housing market, a major consumer of the country's cement, flat glass and aluminum, showed more signs of cooling, the cement industry managed to lock in a 269-percent upsurge in profits totaling 9.9 billion yuan (1.6 billion U.S. dollars) in the first four months.

Investment in the cement sector followed a weakening real estate market with a year-on-year decline of 2.4 percent to 24.73 billion yuan in the January-April period.

The output of flat glass, another sector closely linked with the property market and fraught with overcapacity problems, also rose 4.3 percent year on year to 268 million weight boxes from January to April, according to the NDRC data.

Flat glass producers increased their profits by 54 percent to 1.33 billion yuan even though they cut investment by 6 percent year on year to 6.64 billion yuan.

Aluminum smelting factories, which rely heavily on the real estate sector for growth, saw their losses widen to 5.26 billion yuan in the January-April period, with a combined output of 7.69 million tonnes.

Of a statistical pool of 70 major Chinese cities, eight cities reported month-on-month declines in new home prices in April while fewer cities reported price gains, according to the National Bureau of Statistics.