China's National Bureau of Statistics (NBS) on Tuesday attributed a discrepancy between industrial output and power generation growth in May to industrial restructuring and the use of energy-efficient products.

Industrial output expanded 8.9 percent in May from a year earlier, while power generation fell 2.7 percent.

Such discrepancies had occurred before, usually when the economy hit a turning point, said the statement.

The statement attributed the faster-than-expected industrial output growth to a rebound in the growth rate of heavy industry, accelerating growth in almost three-quarters of all 39 industrial categories, higher growth rates in 20 of the 31 provincial regions and output gains in quake-hit Sichuan province.