Pasadena nanotech company Arrowhead Research Corp. late Wednesday said it carried out a 1-for-10 reverse stock split of common stock that had been earlier approved by its board and shareholders.

Trading on a post-split basis will begin Thursday morning. The reverse split decreases the number of shares outstanding to about 10.5 million from roughly 105 million. The shares available under the company’s equity-based plans also will be proportionately reduced.

The reverse split is designed to increase the stock’s per-share price and help meet the listing requirements of Nasdaq, which has sent the company several delisting warnings.

Arrowhead is a holding company that owns and has stakes in companies developing treatments in oncology, obesity, and regenerative medicine. A nanotech approach to medicine frequently employs the use of tiny particles or molecules to improve the effectiveness of drugs and other treatments.

Shares earlier closed down 4 cents, or 6.5 percent, to 65 cents on the Nasdaq.