Shenzhen's Growth Enterprise Board (GEB) released a memorandum on its website Tuesday restricting the use of over-raised funds from IPOs launched on the board, but the move was followed Wednesday by eight companies fixing their issuance prices higher than had been expected.

Combined, the eight companies stand to raise 2.5 times the amount of money that had been expected under previous estimates of what their issuance prices would be. The GEB's new restrictions are designed to regulate the way such over-raised funds can be used in a bid to curb high-risk investment.

The memorandum states that over-raised funds shall be used for the main businesses of listed companies, and not for high-risk securities investment, entrusted finance management, derivatives investment, venture investment, or financing of other parties or individuals.

Listed companies shall make plans for the use of over-raised funds based on the company's development planning and actual production and operational needs within the 6 months following the collection of the funds, the memorandum said on its website.

"The memorandum is really necessary, and will enhance the safety and use of over-raised funds of listed companies, and protect the interest of investors," Zhao Xijun, deputy director of the School of Finance at Renmin University of China, said Wednesday.

But Zhao said the memorandum's impact on the use of funds for high-risk investments is unclear, because it has just been released and needs to be put to the test.

None of the eight companies that fixed their issuance prices Wednesday have actually raised any money yet, but new stocks are widely over-subscribed on Chinese exchanges, as investors consider them a safe bet to rise above their issuance prices. Provided investors remain eager for the eight companies' stocks in light of the newly-raised issuance prices, the firms can expect to raise far more in their IPOs than they had estimated in reports they submitted to the review committee of the China Securities Regulatory Commission (CSRC).

Hubei TECH Semiconductors Co. is expected to over-raise the least among the eight, at 133.77 percent of the figure listed in its previous reports. Another of the firms, Dingli Communications Co. in Zhuhai, could raise 479.53 percent more than it had planned.

But fundamental issues still need to be fixed if regulators want the GEB to run well, Liu Shengjun, deputy director of CEIBS Lujiazui International Finance Research Center, said Wednesday.

"The board is currently too small and can be easily manipulated by investors, and that is why the over-raised phenomenon always developes," Liu said, adding that the GEB still needs expansion to avoid speculation.

Once listed, the eight firms will bring to 50 the number of companies on the GEB, which was launched in October.