China's State Council has approved the expansion of the Shenzhen Special Economic Zone (SEZ) to almost five times its current size in a move aimed at accelerating the city's development, the Shenzhen legislature announced Wednesday.

From July 1, the city's Baoan and Longgang districts would be incorporated into the SEZ, increasing its total area to 1,953 square km from 396 square km at present, officials said at a press conference.

The move is expected to offer more space to enhance Shenzhen's scientific innovation capacity and to balance development in the city, one of China's first group of SEZs set up in 1980, according to the approval.

SEZs were considered showcases of China's reform and opening-up when they were launched more than 30 years ago.

"The expansion indicates that the central government wants the 30-year-old SEZ to continue its innovation drive and try to catch up with international practice," said Song Ding, a researcher with the city's Academy of Comprehensive Development.

The move was expected to close the huge economic gap between regions in and outside of the SEZ area, which would eventually benefit residents and attract more investment, mostly from neighboring Hong Kong, said Guo Shiping, professor of economics at Shenzhen University.

Compared to Luohu, Futian and other regions within the SEZ, Baoan and Longgang were underdeveloped and less economically efficient.

The city had been implementing two systems of polices for areas inside and outside the SEZ, causing much inconvenience in urban administration and leading to public discontent over unequal treatment.

By reforming land use and upgrading infrastructure construction in underdeveloped areas with government funds, the investment environment was expected to improve in three to five years, said Song.

The Shenzhen government had drawn up a plan to allocate 45 billion yuan (6.6 billion U.S. dollars) to Baoan and Longgang this year for projects, including environmental protection, road and housing construction, and high-tech zone development, which accounted for 72 percent of the overall funds for the whole city, said Chen Biao, director of the Development and Reform Commission of Shenzhen.

Hong Kong and the wider world would benefit from Shenzhen's expansion as investors would have more investment opportunities in a larger area, said Guo.