The Standard & Poor's rating agency cut China's credit rating Thursday due to its rising debts, highlighting challenges faced by Communist leaders as they cope with slowing economic growth.
The downgrade added to mounting warnings about the dangers of increasing Chinese debt, which has fueled fears of a banking crisis or a drag on economic growth. Moody's Investors Service cut its own rating for China in May.
S&P lowered its rating on China's sovereign debt by one notch from AA- to A+, still among its highest ratings. The agency had given a warning sign of a possible downgrade in March 2016 when it changed China's outlook to negative.
"A prolonged period of strong credit growth has increased China's economic and financial risks," S&P said in a statement. "Although this credit growth had contributed to strong real GDP growth and higher asset prices, we believe it has also diminished financial stability to some extent."
The ratings cut, announced after Chinese financial markets closed for the day, could raise Beijing's borrowing costs slightly, but the more significant impact is on investor sentiment.
Phone calls to the Chinese Finance Ministry were not answered. After the Moody's downgrade in May, the ministry said the agency had used improper methods and misunderstood China's economic difficulties and financial strength.
Communist leaders have cited reducing financial risk as a priority this year. They have launched initiatives to reduce debts owed by state companies, including by allowing banks to accept stock as repayment on loans. But private sector analysts say they are moving too slowly.
Beijing relied on repeated infusions of credit to prop up growth after the 2008 global crisis.
That helped propel total nongovernment debt to the equivalent of 257 percent of annual economic output by the end of last year, according to the Bank for International Settlements. That is unusually high for a developing country and up from 143 percent in 2008.
Chinese economic growth fell from 14.2 percent in 2007 to 6.7 percent last year, though that still was among the world's strongest.
The government is trying to make the economy more productive by giving market forces a bigger role. It is trying to shrink bloated industries such as steel and cement in which supply exceeds demand, which has depressed prices and led to financial losses.
Beijing is trying to steer the economy to slower, more sustainable growth based on domestic consumption instead of investment and exports. But growth has dipped faster than planners wanted, raising the risk of politically dangerous job losses. Beijing has responded by flooding the economy with credit.
Official efforts to rein in debt "could stabilize the trend of financial risk in the medium term," S&P said. "However, we foresee that credit growth in the next two to three years will remain at levels that will increase financial risks gradually."
S&P kept its outlook for China stable. It said that reflected expectations the country will "maintain robust economic performance over the next three to four years."
"We may raise our ratings on China if credit growth slows significantly and is sustained well below the current rates while maintaining real GDP growth at healthy levels," S&P said. "A downgrade could ensue if we see a higher likelihood that China will ease its efforts to stem growing financial risk and allow credit growth to accelerate to support economic growth."