Prices for goods at the factory gate in China missed expectations in May, the government said Friday, in a possible sign of weakening demand for the world's second-largest economy.

The producer price index (PPI) rose 5.5 percent year-on-year in May, according to the National Bureau of Statistics, slightly lower than economists' expectation of a 5.6 percent increase in a Bloomberg News survey and down from a 6.4 percent gain in April.

The consumer price index (CPI), a main gauge of inflation, rose 1.5 percent year-on-year in the month, the data showed.