BEIJING - China's economy will expand at 8.4 percent this year, up from the 7.8-percent growth rate of 2012, a research institute under the country's top science academy has predicted.

China, the world's second-largest economy, will see a mild pick-up in 2013 amid sluggish external demand, according to a report released on Saturday by the Center for Forecasting Science under the Chinese Academy of Sciences.

Chen Xikang, deputy director of the center's academic committee, said that difficulties still loom large over China's recovery process as investment and export take up too big a proportion of the economic structure and consumption still remains weak.

China's strict property curbs and economic restructuring will also affect the growth rebound, he added.

On a quarterly basis, the growth rate is expected to accelerate in the first and second quarter of 2013, and gradually draw back in the middle of the year before picking up again in the fourth quarter, the report said.

China's economy recorded 7.8 percent year-on-year growth last year, marking the first time that the annual increase dropped to less than 8 percent since 1999, according to data released on January 18 by the National Bureau of Statistics (NBS).

"The growth rate did slow last year but still remains at normal levels, which will not change the basic development pattern of China's economy in the medium-to-long term," said Zhu Baoliang, a researcher with the State Information Center, a government think-tank.

In breakdown, the value-added in the country's primary, secondary and tertiary industry will grew at 4.7 percent, 8.9 percent and 8.8 percent, respectively, according to the new report.

Consumption and investment will contribute 4.5 percent and 4.2 percent, respectively, to the country's economic expansion in 2013, it said.

It also predicted that the combined imports and exports volume will grow by 8.5 percent year on year, with imports up 8.6 percent and exports up 8.3 percent from the previous year.

Chen expects the consumer price index (CPI), a main gauge of inflation, to expand at 3.5 percent year on year in 2013, faster than last year.

The country's CPI grew 2.5 percent year on year in December 2012, up from 2.0 percent in November and 1.7 percent in October, bringing the full-year increase to 2.6 percent, according to data from the NBS.

Both Chen and Zhu urged government to strike a balance between a sound economic growth rate, well-implemented structural adjustment and inflation control under the condition of a stabilizing economy.

They also called for a steady monetary policy to stimulate the real economy and more tax measures to cool the runaway property market.