The San Diego-based company, which has suffered a series of missteps recently, did not say why Jay Tanna was stepping down. A spokesman declined to comment.
Altris said that it has appointed Roger Erickson to take over as its new chief. A 15-year Altris veteran, Erickson most recently served as the company's vice president for strategic partners.
The chairman of the board slot will remain vacant. Former chairman of the board Robert Bruce now will act as a consultant to the company.
Last month, Altris said it was reviewing its earnings reports for all of 1996 and the first nine months of 1997, and cautioned that "a significant downward restatement of previously reported revenues" was likely to result. Trading of the company's stock immediately was halted on the news, and has not yet resumed. Currently, Altris' stock is priced at 2-5/32 per share.
The company also has been hit with a shareholder lawsuit alleging violations of securities laws.