June 22 (Bloomberg) -- As U.S. regulators confront a new wave of insider-trading cases on Wall Street, one presidential candidate is uniquely positioned to tout his background fighting white-collar crime: Rudy Giuliani.

Giuliani made a name for himself two decades ago as a U.S. attorney by cracking down on corporate crime, nabbing financier Ivan Boesky and junk-bond trader Michael Milken and forcing other executives to parade before the cameras in handcuffs.

Nowadays, he rarely mentions those headline-making moves when stumping for the Republican Party nomination, highlighting instead his national-security credentials and role in reviving New York's economy during his eight years as mayor. At the same time, Giuliani, 63, has emerged as a top recipient of campaign contributions from the industry he once targeted.

``One of the reasons he doesn't call attention to the past is that he's been in a political campaign mode for many years now, and he has drawn support from among hedge funds and investment-banking firms, and some of the very places he used to investigate,'' said Chuck Gabriel, a longtime political strategist for institutional investors.

Through March 31 of this year, Giuliani reported raising $1.8 million from securities and investment firms. That's more than any presidential candidate except Republican rival Mitt Romney, the former Massachusetts governor, who got $1.9 million, according to the Center for Responsive Politics, a Washington- based nonprofit group that tracks campaign donations.

Surge in Cases

The U.S. Securities and Exchange Commission has filed more insider-trading lawsuits against investment bankers, analysts and executives in the last 15 months than it did throughout the entire 1990s. When asked about the recent spate of cases in a June 13 interview, Giuliani said the problem was cyclical.

``It's almost something that's always going to be with us,'' he said. ``You are going to have periods of regulation and cracking down and people are going to stop. Then they'll forget, and you'll have to do it again.''

Though Giuliani doesn't say much about his work as U.S. attorney, his campaign Web site says he ``spearheaded successful efforts against organized crime, white-collar criminals, drug dealers and corrupt elected officials.''

Campaign spokeswoman Maria Comella said he talks about his days as a prosecutor ``in the context of his record and pointing to that as one of the reasons why he's best qualified'' to be president.

Opposing Tax Bill

Giuliani this week signaled a sympathetic attitude toward the industry by opposing a U.S. Senate bill that would tax private equity firms' profits at the higher corporate rate when they take their companies public, as the Blackstone Group did today. The bill would mean Blackstone's tax rate would jump to 35 percent from the 15 percent it paid as a private partnership.

Giuliani views the bill ``as a tax increase, and the last thing we need right now is another tax increase,'' Comella said.

As U.S. attorney for New York's Southern District from 1983 to 1989, Giuliani rocked Wall Street, bringing insider-trading cases against some of the most successful investment bankers of the day. The defendants included Martin Siegel, a Kidder Peabody & Co. banker; Milken, the former head of the junk-bond department at Drexel Burnham Lambert Inc.; and Boesky, a stock-market arbitrager whom Giuliani accused of capitalizing on insider information.

Largest Fine

Boesky pleaded guilty to one count of conspiracy in 1987 and paid a $100 million fine, at the time the largest levied for a securities law violation. He served three years in the minimum- security federal prison in Lompoc, California, one of the correctional facilities that became known as ``Club Fed'' for its swelling population of well-treated white-collar criminals.

Giuliani also got Boesky to help build his case against Milken, a former Boesky associate, offering a more lenient sentence in return for his testimony.

Milken pleaded guilty to securities fraud in 1990 and served two years in prison. Milken declined requests for an interview. Attempts to contact Boesky were unsuccessful.

While Giuliani is credited with prosecuting big names like Boesky and Milken, his tactics on cases of lesser-known figures still draw criticism for pushing the boundaries of prosecutorial discretion.

In February 1987, federal agents led Richard Wigton, then the 52-year-old head of Kidder Peabody's arbitrage desk, off the trading floor in tears and handcuffs for allegedly having illegal dealings with Boesky. Several months later, the charges were dropped. Wigton never worked on Wall Street again.

Targeting Goldman

That same day, agents went to the Manhattan offices of Goldman Sachs & Co. and hauled off a handcuffed Robert Freeman, an assistant to Robert Rubin, then a top executive who later became President Bill Clinton's Treasury secretary.

Freeman was also charged with insider trading. He eventually pleaded to a single count of using non-public information for trading in 1990 and served a four-month prison sentence. Rubin declined to discuss his views on Giuliani.

Stanley Arkin, Wigton's lawyer at the time, said the public arrest was akin to ``spitting in the face of the presumption of innocence.''

Arkin praised Giuliani as a talented lawyer and said a lot of what he did on Wall Street ``ended up being very good.'' Still, he says the Wigton case ``demonstrates a quality of ruthlessness'' that ``goes very much to the roots of the kinds of judgments that are made when you have an eye on the headlines.''

Stanley Sporkin, a former U.S. district judge for the District of Columbia who was head of enforcement for the SEC from 1974 to 1981, said while there were ``excesses,'' Giuliani was ``the right man for the right time.''

``He was tough,'' Sporkin said. ``And if you're tough, you do things that other guys might not do.''

To contact the reporters on this story: Catherine Dodge in Washington at Cdodge1@bloomberg.net; Henry Goldman in New York at hgoldman@bloomberg.net.

Last Updated: June 22, 2007 16:57 EDT