BEIJING, July 4 (Xinhua) -- Twenty-eight Chinese companies that have obtained permission from the securities watchdog for initial public offerings (IPOs) announced Saturday evening they would postpone follow-up issue of shares due to recent fluctuations in the stock market.

The companies, 10 to go public in Shanghai and 18 in Shenzhen as planned, said they have adjusted their IPO schedule and would start to refund investors' capital on July 6, according to the announcements filed with the Shanghai and Shenzhen stock exchanges.

Analysts believe the postpone will help relieve the market which is in urgent need to rein in continued plunge. A string of supportive measures were rolled out in the past days but failed to reverse the losing trend.

The Shanghai Composite Index dived 5.77 percent on Friday to finish at 3,686.92 points, down substantially from a peak of 5,178.19 points on June 12.