SHANGHAI (AFP) - China's economic growth must not slip below the "bottom line" of 7 per cent, Premier Li Keqiang said.

"The bottom line for economic growth is 7 per cent, and this bottom line must not be crossed," Mr Li told a meeting earlier this month, the state-backed Beijing News reported on Tuesday.

The target was necessary to ensure China achieved its goal of doubling its gross domestic product between 2010 and 2020, he told economic experts and business representatives.

China has risen to become the world's second-largest economy in recent years, but concerns have been raised over growth, which is vital to the ruling Communist party's delivery of promised prosperity.

The economy expanded 7.5 per cent year-on-year in the April-June period this year, slowing from 7.7 per cent in the first quarter and 7.9 per cent in the last three months of 2012.

The government has set a full-year growth target of 7.5 per cent for 2013.

An official government statement previously quoted Mr Li as telling a meeting on July 16 that the economy must be kept within "a reasonable range".

He said the "lower limit" was to stabilise economic growth and maintain employment while the "upper limit" was to prevent inflation, according to the statement on the government's official website.

That release gave no numerical targets for economic growth.

Chinese authorities have been trying to rebalance the economy through long-term structural reforms, but Mr Li's remarks sparked hopes the government may shift its focus back to maintaining growth, analysts said.

"We reckon that he could introduce a small-scale fiscal expansion by tapping the central government coffer to support social housing, railway, environment related urban infrastructure such as sewage," economist Lu Ting with Bank of America Merrill Lynch, said in a research note on Tuesday.

Chinese shares rose 1.61 per cent in afternoon trading on Tuesday, lifted by hopes for policies to support the domestic economy.