A federal jury found Nathan A. Chapman Jr. guilty of 23 felony offenses Thursday, concluding that the politically connected investment banker defrauded the Maryland state retirement system of nearly $5 million and looted hundreds of thousands of dollars from companies under his control.

The verdicts, after a nine-week trial, were a sound defeat for a pioneering African American businessman who once dreamed of creating a "black Merrill Lynch."

The son of a seamstress and a railroad laborer, Chapman ascended into the exclusive world of high finance, building businesses that at one point managed more than $800 million and occupied offices on the top floor of Baltimore's World Trade Center.

Jurors found that Chapman used state pension money under his management to invest in his own businesses, losing millions when his company's stock price fell during the market downturn of 2000.

They also found that he took company money intended for business-related expenses and used it instead for personal indulgences. Jurors did not agree on the amount involved, but prosecutors alleged that Chapman took more than $500,000, spending a portion of it on an extravagant life and extramarital affairs.

Chapman, 46, did not visibly react as the verdicts were read. He seemed to gaze into the middle distance and later ignored a throng of reporters outside U.S. District Court.

"Nathan Chapman walked away today a disappointed man, but a man who still believes he's innocent," his lead attorney, William R. "Billy" Martin, said outside court.

Chapman was allowed to remain free until his sentencing Nov. 1. Lawyers on both sides declined to say how long a sentence they expect him to receive, but sentencing guidelines appear to suggest a term of close to five years.

In and out of court, defense attorneys said that prosecutors invested huge resources in trying to build a criminal case against former governor Parris N. Glendening (D), a close friend and political ally of Chapman. After authorities failed to muster enough evidence to indict Glendening, the defense attorneys alleged, they went after Chapman as a consolation prize.

Witnesses testified that Glendening and others in his administration personally lobbied to increase the amount of pension money under Chapman's management.

Jurors, returning verdicts on their seventh day of deliberation, found Chapman guilty on 15 counts of wire fraud, two counts of mail fraud, three counts of investment advisory fraud, one count of making false statements to a government agency and two counts of making false statements on tax returns. He was acquitted on two wire fraud counts, four mail fraud counts and one count of making a false statement. The jury could not agree on two other counts of making false statements on tax returns.

Chapman was acquitted of charges relating to cash and gifts he lavished on Deborah B. Humphries, a pension board member with whom he had an extramarital affair.

The $30 billion state pension fund serves more than 275,000 teachers, police officers and other government workers. The pension board entrusted $140 million to Chapman to manage. The case also covers his handling of money from two other pension funds.

The verdict was a victory for U.S. Attorney Thomas M. DiBiagio, who in the midst of the trial became embroiled in a controversy -- he was rebuked by his superiors for pressing prosecutors to deliver three "front-page" indictments by early November -- that defense attorneys sought to use to their advantage. DiBiagio alluded to the criticism in comments to reporters Thursday, saying federal prosecutors are dedicated to rooting out abuses of trust "regardless of the power and prestige of the defendants."

"This dedication and effort is driven not by a political agenda . . . not by any personal ambition but rather by a genuine sense of duty to the public," DiBiagio said.

DiBiagio declined even to say whether Chapman faces "months or years" in prison. "I would just be guessing," he said. "I have no idea."

In answer to a reporter's question about whether Chapman might now cooperate with the government on related investigations, Martin said: "Mr. Chapman is always open to being reasonable, but I don't think there is any testimony Mr. Chapman has that can in any way further any of their investigations."

Martin said the case would be appealed, calling the verdict "the first step in a very long road."