Chinese economy has bottomed out and is stabilizing against the global economic downturn, but it would go through a U-turn recovery as a quick recovery could hardly be sustained, a researcher with the country's top think tank said here Sunday.

"Although the economy has bottomed out, it was touching a flat bottom, instead of a V-shaped bottom," said Zhang Wenkui, deputy director of the enterprise research institute under the Development Research Center of the State Council, a government think tank, at a forum.

However, China's recovery will be "very mild" and "unstable", and a quick, stable, and sustained recovery is not likely, he said.

Zhang said he made the predictions on the performance of three drivers of the economy, namely investment, export and consumption.

China's fixed asset investment jumped 30.5 percent in the first four months, however, the robust growth was mainly a result of investment on government-sponsored infrastructure projects, and investment in the manufacturing sector was still lower than in previous years, he said.

This showed manufacturers are not very confident in the future growth in demand, he added.

China's exports merely increased 17.2 percent last year, and even fell 22.6 percent in the first four months, making negative contribution to the overall economy at present, Zhang said.

China's consumer spending was very strong, and consumer demand, as gauged in retail sales, expanded 14.8 percent year on year in April, but the growth was weaker than that of last year, said Zhang.

He also cited other figures indicating a recovery in the economy, such as the industrial output, which grew 8.3 percent and7.3 percent in March and in April, respectively, an acceleration from 3.8 percent in the first two months.

He expressed optimism in the world's largest economy, saying the economy would return to the track of fast growth in two or three years, adding that demand for auto, housing, and computers would fuel the growth.

Zhang said the government is likely to roll out more stimulus measures in the third quarter to bolster the economy.