Spending on factories and real estate may have jumped 25.3% in the first four months of 2007 from a year earlier. The figure was the median estimate from 19 economists surveyed by Bloomberg . Official figures from the National Bureau of Statistics are scheduled to be released on May 17. The increase suggests China's central bank may need to raise interest rates to cool investment once again. Last year, urban fixed-asset investment jumped 29.6% during the same period. The continued increase in investment increases the risks of China being saddled with idle factories and bad loans if there is an economic slowdown. "Three more interest rates hikes are likely before the end of the year — at a minimum," said Michael Kurtz, an economist at Bear Stearns Asia in Hong Kong. Throughout 2006, fixed asset investment jumped 24.5%.