Production growth in China's machinery sector slowed sharply in the first half of 2015, an industry association said on Thursday, predicting a moderate rebound amid grim conditions.

The China Machinery Industry Federation (CMIF) said the sector expanded just 5.7 percent in the first six months, while the growth was 11.2 percent in the same period last year.

China's total industrial production increased 6.3 percent in H1, and growth in the machinery sector fell short of the national average.

"This was very rare. The slowdown was beyond our expectation," said the CMIF in a statement.

A survey by the federation showed machinery makers were afflicted by shrinking demand, declining orders and dropping prices.

The CMIF attributed the lackluster performance to less investment caused by an economic slowdown.

"The sector may slightly warm up in the latter half of the year to bring annual growth to around 8 percent, as a slew of pro-growth measures will hopefully take effect," the CMIF reckoned.

Annual growth will definitely be lower than the 10 percent increase recorded in 2014, it added.