A Chinese national flag flies in front of a building under construction in the central business district of Beijing, China, on February 1, 2019.

Companies in China are increasingly having difficulty getting paid.

The country's slowing economic growth, tighter credit conditions and rising bond defaults are putting pressure on corporate cash flows, according to a survey by French trade insurer Coface.

Growth in the world's second-largest economy slowed to 6.6 percent in 2018, the worst showing since 1990. Efforts by authorities to rein in high debt levels by constricting credit were a factor behind record corporate bond defaults, while the trade war with the United States also weighed on businesses and consumer spending.

"This context has led to pressure for Chinese companies, who have resorted to using longer payment terms to sustain business," Carlos Casanova, Coface's Hong Kong-based economist for Asia Pacific, said in his firm's China Payment Survey 2019, released Thursday.

The longest payment terms were seen in the automotive and broader transportation sector as well as the construction and energy sectors, according to Casanova's report.

Coface queried 1,500 Chinese companies and found that 62 percent reported delays in getting paid last year.

Many companies have complex supply relationships. Automobile manufacturers, for example, need to procure steel, plastic and electronic components and numerous transactions occur along the supply chain. That dynamic is also at play in other industries, such as construction.

A total of 40 percent of respondents said payment delays increased last year, higher than the 29 percent recorded in 2017.

Coface said 90 percent of the surveyed companies are privately owned while 10 percent are state owned.

Pressure from the slowing economy and the trade war eventually caused authorities to pause last year in their efforts to pare down total debt, estimated at more than three times the size of China's GDP, in order to try and support overall growth.