Arrowhead Research Corp. shares lost a quarter of their value on Thursday after the nanotechnology company said it planned to make a direct offering of stock and warrants that would raise $8.65 million. However, the offering would increase the number of shares outstanding by about 10 percent.

Although shares swooned 26 percent on Thursday, they recovered somewhat in early trading Friday.

The Pasadena holding company, whose subsidiaries focus on the health care and high-tech industries, is selling 6.6 million new shares of its common stock, plus warrants to purchase 3.3 million shares in the next five years. The stock and warrants will be sold in units, at a price of $1.312 per unit.

The company now has 63.9 million shares outstanding and a market cap of $78 million.

Net proceeds from the sale, which is expected to close by June 22, will be invested in current subsidiaries, for new investments, and for operating expenses.

Shares on Friday were up 4 cents, or about 3 percent, to $1.27 in midday trading on the Nasdaq.