BEIJING, June 17 -- China's securities regulator approved IPO applications of only six companies this week.

The companies will raise no more than 3.4 billion yuan (about 500 million U.S. dollars), according to a statement from the China Securities Regulatory Commission (CSRC) late Friday.

Three companies will be listed on the Shanghai Stock Exchange, one on the Shenzhen Stock Exchange's Small and Medium-sized Enterprise Board and two on the ChiNext, China's NASDAQ-style board.

The firms and their underwriters will confirm IPO dates and publish prospectuses following discussions with the exchanges.

Under the current IPO system, new shares are subject to approval from the CSRC.

China is gradually switching from an approval-based IPO system to a more market-oriented one based on registration.