China's private companies have defaulted at a record rate this year and could face similar pressures in 2020, rating agency Fitch said, highlighting significant corporate debt risks as economic growth slows to near 30-year lows.

A record high of 4.9% of China's privately-owned issuers defaulted on onshore bond payments in the first 11 months of 2019, Fitch said in a statement, up from 0.6% of private issuers in 2014.

Privately-owned enterprises (POEs) accounted for more than 80% of bond defaults, whether counting by the number of issuers or the principal amount of defaulted bonds, Fitch said.

Jenny Huang, director of China corporate research at Fitch Ratings, said that she expects the POE default rate "to stay at around this record level in 2020."

China's mounting defaults reflect the struggles of private firms as a slowing economy and high refinancing pressures make it harder for companies to repay debts and take out new loans.

Weaker issuers will face difficult conditions due to Beijing's "selective" efforts to support only more-qualified small and private firms, Huang said.