DENVER – The former chief executive of Qwest Communications International, Joseph Nacchio, was indicted yesterday on 42 counts of insider trading in the culmination of a three-year investigation of possible wrongdoing at the company.

The indictment against Mr. Nacchio was unveiled at a hearing yesterday morning before magistrate Judge Patricia Coan. Mr. Nacchio, 56 years old, has long said he did nothing wrong during his tenure at Qwest, which ended when he was forced out of the company in 2002. If convicted, Mr. Nacchio could face a long jail sentence and heavy fines.

Mr. Nacchio is accused of selling stock while in possession of insider information that the Denver-based phone company was not doing as well as he claimed to the public. According to people familiar with the matter, Mr. Nacchio is expected to claim that his stock sales were entirely legitimate and that he fully believed the company was doing well when he sold the stock to pay taxes and diversify his investments.