More shares from Aastrom Biosciences Inc. (NSDQ:ASTM) and Hanger Orthopedic Group Inc. (NYSE:HGR) are set to hit the market.

Aastrom yesterday priced an offering of 10 million shares at $2.25 a piece on the NASDAQ stock exchange.

News of the offering sent the company’s stock price tumbling. ASTM shares closed at $2.37, down almost 23 percent. The Ann Arbor, Mich.-based company had been threatened with delisting from the market until it brought its share price above $1 in March.

The company hopes to net $20.5 million though the offering, after underwriting fees, and plans to use the funds for "general corporate purposes, including research and development expenses such as expenses related to our [critical limb ischemia] program, capital expenditures, working capital and general administrative expenses," according to a filing with the federal Securities & Exchange Commission. The CLI program’s Phase III clinical trial is slated to launch in early 2011. CLI is a stem cell technology intended to treat cardiovascular diseases.

Hanger Orthopedic yesterday announced the sale of 2 million shares by major shareholder Ares Corporate Opportunities Fund LP, which will still own more than 3 million shares — about 9 percent — of the company, according to an SEC filing.

Ares priced the offering at $20.00 per share. HGR shares traded for $21.04 the night before the Austin, Texas-based orthotic and prosthetic device developer announced the offering.

Hanger share prices fell just half a percent when news of the offering broke, closing at $20.94.

The transactions for both companies are expected to close Dec. 15.