(Adds details on IPO approvals, background)
SHANGHAI, Feb 2 (Reuters) - Medium-sized Chinese brokerage Dongxing Securities Co Ltd said late on Sunday that it aimed to issue up to 500 million shares in an initial public offering (IPO) in China's main Shanghai Stock Exchange to raise funds to supplement its working capital.
The shares, which will account for 19.97 percent of the company's expanded outstanding shares after the IPO, will be open to subscriptions around Feb 10, the company said in a prospectus published in the exchange's website.
It did not say how much proceeds it aimed to raise.
The China Securities Regulatory Commission (CSRC) announced it approved 24 IPOs on Friday, the second batch approved in January, as it boosts supplies of new shares to help cool a red-hot stock market. Last year, the CSRC approved about 10 IPOs per month.
More than half of the companies given the go-ahead last month, including Dongxing, published their share issue prospectuses late on Sunday.
Many Chinese investors see such approvals as watering down net valuations as they will compete with already listed companies for the same pool of funds.
China's blue-chip CSI300 Index jumped 52 percent in 2014, becoming the world's best-performing main stock index, driven partly by government reforms.
Dongxing Securities' net profit surged 56 percent to 1.04 billion yuan ($166 million) in 2014 from 2013, it said in the prospectus.
$1=6.25 Yuan Reporting by Lu Jianxin and Sue-Lin Wong; Editing by Pete Sweeney and Stephen Coates