China's machinery manufacturers will face tougher markets both domestically and overseas due to falling demand and the weak global economy, industry experts said on Tuesday.

According to data provided by the China Machinery Industry Federation, year-on-year growth of fixed-asset investment in the machinery sector in the first half of the current year was 3.07 percent, the lowest level since 2008.

Vice-President Chen Bin said the steel, coal, construction and oil industries experienced less demand during the period, which resulted in the slowdown in machinery investment.

"The machinery industry mainly serves those sectors. There is no sign of a rebound for those industries, which has led to our expectations for the machinery sector in the second half of the year continuing to be low," he said.

Chen said orders were not stable and the number of orders for the first six months grew by only 4.8 percent.

The export market, meanwhile, has been facing challenges posed by a weak world economy.

"Some countries are taking trade protectionist measures to help their own companies, which added to our difficulties in the export markets," Chen said.

Total exports by the industry in the first half stood at $182 billion in 2016, down 6.42 percent from last year, while imports during the same period dropped 7.51 percent to $127.8 billion.

Exports by China's private companies, which used to be the mainstay of the country's machinery exports, have been declining since the start of the year. Previous double-digit growth has turned to negative growth, the federation said.

For the first half, exports from the private sector declined by 0.66 percent year-on-year.

Export volumes by traditional large export provinces, including Jiangsu, Zhejiang and Guangdong, dropped by 2.55 percentage points to 5.47 percent year-on-year in the first half.

"The companies have to accelerate innovation in the manufacturing sector by closely cooperating with scientific and research institutions," Chen said.