BEIJING, May 1 (Xinhua) -- The cycle of economic boom in China, the world's fastest-growing major economy, would last until at least 2020, said an expert with the National Development and Reform Commission (NDRC), the top economic planner.

　　The cycle, which started in 1978 when the reform and opening-up drive was launched, saw the country's economy grow 9.88 percent annually during the past 30 years, said Chen Dongqi, vice president of the NDRC's Academy of Macroeconomic Research.

　　"China's economy saw a marked slow down in the first quarter as the U.S. credit crunch bit," Chen told a recent forum held in Nanning, capital of the southern Guangxi Zhuang Autonomous Region.

　　The economic growth slowed to 10.6 percent in the first quarter from 11.7 percent a year earlier, because of slower export growth and the worst winter in more than five decades.

　　Last year, the economy expanded 11.9 percent, the fifth year of double digit growth.

　　"Industrial output in the Pearl and Yangtze river deltas, the nation's two most important growth engines, rose at an marked slower pace," he stated.

　　"Many small- and medium-sized companies, particularly the exporters of low-end products, are faced with huge growth difficulties."

　　The rapidly-rising yuan and raw materials and labor costs have also put the squeeze on profits of local businesses.

　　Chen, however, acknowledged the economy still had much room for growth despite the current negative factors.

　　"(We) don't need to worry about the long-term economic boom just because of the short-term impact," he said. "The growth will be robust at least till 2020, especially in regions such as the West and the Beibu Bay Economic Zone in Guangxi.

　　"The economy is rather dependent on exports, but we still have huge room to deepen and expand the opening-up," he noted. "The investment in the rapid urbanization process will also be a strong driver behind the economic growth."

　　The expert added the rapidly growing tertiary sector and an increasingly larger proportion of the new workforce would also make bigger contributions to the economic boom.