Rigaku's shares slumped 10% in their market debut on Friday, after buyout firm Carlyle Group steered the Japanese X-ray testing tool maker to an $863 million initial public offering (IPO).

Shares traded at ¥1,125 ($7.41) in the morning after initially being untraded with a glut of sell orders, and closed at ¥1,130.

The company had priced the IPO at the top end of a ¥1,230 to ¥1,260 indicative range.