Attorneys for money manager Nathan A. Chapman Jr. on Tuesday called the prosecution of their client "politically motivated" and argued that jurors should be told that U.S. Attorney Thomas M. DiBiagio was recently rebuked for seeking "front-page" indictments in public corruption and white-collar crime cases.

In a filing at U.S. District Court, Chapman's defense team argued that the admonishment from the Department of Justice is relevant because the indictment against Chapman "was authorized by the same United States Attorney whose motives for pursuing public corruption cases are now in question."

Judge William D. Quarles Jr. did not immediately rule on the request, filed late on the second day of the defense case. Prosecutors, who have acknowledged investigating ties between Chapman and officials in former governor Parris N. Glendening's administration, argued preemptively Monday that the controversy would distract from the criminal charges against Chapman and should not be mentioned in front of the jury.

Chapman, who once managed more than $140 million from the state pension fund, is charged with defrauding the fund by investing a portion of that money in his own struggling companies, losing nearly $5 million from the fund in the process.

Also Tuesday, the defense challenged a pillar of the government's case: The allegation that Chapman compelled investment adviser Alan B. Bond, who managed a portion of the assets under Chapman's control, to invest pension money in at an inflated price when the financial services firm went public in June 2000.

The government alleges that Bond, under Chapman's direction, used pension money to buy 175,000 shares at $13 each when shares were trading publicly at $7. A former trader who worked for Chapman has testified that Earl Bravo, chief operating officer for one of Chapman's companies, ordered her to backdate the transaction, resulting in an immediate loss of more than $1 million. Bond's testimony, obtained under a grant of immunity, has generally supported that account.

Bravo, who remains a Chapman employee, disputed the assertion Tuesday. He said the company turned to Bond after another investor did not honor a commitment to participate in the initial public offering. He suggested that Chapman had told him that Bond had previously agreed to such an arrangement.

The trader, Sonya Mitchell, had testified earlier that "when I processed that trade, I knew it was a fraud."

Bravo described her as an "abusive" employee whose errors cost the company nearly $100,000 in three months. After she was fired in March 2001, Bravo said, "I learned that she was very upset about my terminating her and she was going to get me and the company and she was going to go to the [Securities and Exchange Commission] and put us out of business."

In its motion, Chapman's defense team seized on DiBiagio's frequent declarations that public corruption is a top priority, and on an e-mail -- disclosed last week by the Baltimore Sun -- in which he told his prosecutors that he was "embarrassed" that the office has not convicted an elected official of corruption since 1988.

"It appears from the evidence elicited to date that the U.S. Attorney and his staff viewed this case as an opportunity to finally establish a political corruption case, and that they 'pulled no punches' in this effort," the defense team wrote. "In pursuing this investigation, the U.S. Attorney has expended significant government resources for improper purposes, possibly including his own political ambitions."

A spokeswoman for DiBiagio said he would not comment.

Superiors at the Department of Justice admonished DiBiagio on Friday, a day after the Sun published a report based on documents in which he asked his prosecutors to deliver three "front-page White Collar/Public Corruption" indictments by Nov. 6, four days after the presidential election.

James B. Comey, the deputy attorney general, said that to protect the credibility of the office, he would have to personally sign off on any future public corruption cases brought by DiBiagio.

Bravo's testimony offered the most emotional moments yet in a trial now in its sixth week. He spoke of Chapman's dream of creating a "black Merrill Lynch" and of the company's 1993 move into Baltimore's World Trade Center, and he appeared near tears as he described watching the value of stock plummet on June 20, 2000.

Bravo said he and others were devastated by the stock's fall.

"Break your heart?" asked William R. "Billy" Martin, Chapman's attorney.

"Still does when I think about it," Bravo responded. "I guess we were blindsided by forces beyond our control."

Another witness, former board member Theron Stokes, testified that he, too, expected the company to be more successful. He suggested that the government's investigation was at least partly to blame. "But for this political witch hunt, this company would be doing well," he said.

On Thursday, Isiah Leggett, chairman of the state Democratic Party, used almost identical language against DiBiagio. He accused DiBiagio's office of conducting "political witch hunts" and called for his resignation.

Attorneys for Nathan A. Chapman Jr. are contending that his prosecution is politically motivated.