Sales by China's major excavator producers maintained double-digit growth in July, according to the China Construction Machinery Association.

The country's 25 leading excavator makers sold 11,123 units in July, up 45.3 percent year on year, though the growth was milder than a 58.8-percent increase in June.

In July, 9,316 units were sold in the domestic market, up 33.2 percent year on year. Overseas sales soared 171 percent to 1,786 units.

A total of 131,246 excavators were sold in the January-July period, up 58.7 percent over the same period of last year. More than 120,000 of those were sold in the domestic market.

Sales of excavators are an indicator of the vitality of an economy as demand is usually backed by growth in mining, construction, and infrastructure investment.

In the first half of this year, China's fixed-asset investment expanded 6 percent year on year, with growth accelerating in manufacturing and private investment, according to the National Bureau of Statistics.