Evan G. Greenberg, the last member of his family to head a major insurance company, is walking a fine line, staying on his feet despite investigations into the U.S. insurance industry that have toppled his brother and father.

A son of industry icon Maurice R. "Hank" Greenberg, 50-year-old Evan heads Ace Ltd., a major Bermuda-based insurer that is one of the most profitable in the industry. The company is a big underwriter in Asia and a leading U.S. insurer against big corporate losses, such as those from asbestos claims.

Evan Greenberg has so far managed to keep a low profile and mollify authorities -- unlike his father, who was ousted in March after heading giant American International Group Inc. for 37 years, and older brother Jeffrey, who resigned last fall as chief executive of Marsh & McLennan Cos. after New York state Attorney General Eliot L. Spitzer filed civil bid-rigging charges against the company and publicly signaled his desire for Jeffrey W. Greenberg's ouster.

In comments to investors, Evan Greenberg has acknowledged his own company's shortcomings and called for industry-wide reforms. But he also said Ace has weathered an internal review of bid-rigging allegations without major findings of wrongdoing beyond those disclosed earlier this year. At the time of the disclosure, Ace fired three executives, suspended two others and forced the resignation of the head of its U.S. operations, who reported to Greenberg.

"We are an ethical company," he said on a conference call in May. "We have conducted ourselves in a fit and proper manner."

Greenberg has decided to fight a civil suit filed by Connecticut Attorney General Richard Blumenthal alleging that Ace paid an improper secret commission to Marsh to win a state contract to administer $80 million in workers' compensation claims.

Greenberg has said the company believes the case has no merit, and Ace has a filed a motion to dismiss the claim.

Some observers say the company is confident that Greenberg will weather the industry-wide investigations.

"ACE believes its CEO is not a focus of any investigation, despite having the last name Greenberg," J. Paul Newsome, an analyst for A.G. Edwards & Sons Inc., wrote in April. Newsome added recently that he has not learned anything since then to contradict that notion.

Greenberg and Ace, through a company spokesman, declined to comment.

The company faces plenty of questions. According to documents Ace filed in March with the Securities and Exchange Commission, the company has received 43 subpoenas, civil demands and other queries from attorneys general in 10 jurisdictions, including the District, and 10 state insurance departments or other regulators, including Maryland's.

State authorities are investigating whether insurance firms took kickbacks or colluded with one another to increase prices. State and federal officials are also looking into whether companies misled investors by accounting for a type of insurance as a loan when there was no transfer of risk.

Greenberg himself has cautioned that the company is still conducting the second half of a two-part internal review into the company's use of "finite risk" insurance, an income-smoothing device misused by some companies to cover up problems on their books. Allegations of such misuse sparked investigations into AIG and Berkshire Hathaway Inc.'s General Re Corp. insurance unit. The internal review of Ace, by Mary Jo White, a former U.S. attorney for Manhattan and a partner at Debevoise & Plimpton LLP, is due in a month or so.

There are also ongoing state and federal investigations into accounting and business practices at AIG, where Evan Greenberg worked for 25 years, including the last three as chief operating officer under his father.

For a long time, Evan Greenberg was considered the least likely family member to run an insurance company. His father had run AIG since 1967 and turned it into the world's largest insurer. His brother Jeffrey, a graduate of Choate School in Connecticut, Brown University and Georgetown law school, joined a Marsh insurance-brokerage unit and rose quickly. He joined AIG in 1978 and was considered a potential successor to his father, until the two fell out and Jeffrey abruptly left in 1995. He later became head of Marsh, a big source of business for AIG.

Evan, by contrast, did not graduate from college and drifted after finishing at an alternative high school, working as a cook in a nursing home and as a bartender before joining an AIG subsidiary in Colorado in 1975.

Evan served in posts in Korea and Japan and was named to head AIG's foreign general insurance business. He returned to New York in the early 1990s and was named president and chief operating officer in 1997.

As part of his duties, Evan oversaw AIG's auto warranty business, which turned into a "disastrous" investment resulting in a $210 million loss by 1999, according to a civil fraud suit filed by Spitzer against AIG last month. In lengthy litigation brought in 1999 against AIG by a claims adjuster, Warrantech Automotive of Bedford, Tex., Evan Greenberg testified in a 2001 deposition that his father held him responsible for the debacle.

"I received the CEO's displeasure with the business, and how bad it was, routinely; his impatience, his unhappiness and his expectations," he said. The case was first highlighted in a USA Today article published in November.

In September 2000, Evan left.

"We wish Evan the very best in his future endeavors," his father said in AIG news release.

The auto warranty losses became a centerpiece of Spitzer's civil suit against AIG, which alleges that Maurice Greenberg and others arranged a "fraudulent and illegal scheme" beginning in April 2000 to disguise the auto warranty losses as investment losses. AIG says it is cooperating with all investigations. Maurice Greenberg has denied the allegations.

A year after leaving AIG, Evan Greenberg joined Ace, a company packed with AIG alumni and one of AIG's fiercest rivals.

Founded in 1985 to fill an underserved market insuring against large corporate losses, known as excess casualty, the company went on to mimic AIG's core business, commercial underwriting, and became one of the few to compete with AIG both in the United States and globally. The rivalry heated up in 1994, when a top AIG executive and protege of Maurice Greenberg, Brian Duperreault, left AIG to head Ace, taking several AIG executives with him. Maurice Greenberg often disparaged Ace to investors and analysts, sarcastically asking if it was "some kind of bandage," according to people who heard him.

Evan Greenberg was hired in November 2001 to head Ace's overseas unit, became president and chief operating officer in June 2003 and succeeded Duperreault as chief executive in May 2004. He was paid $7.2 million in salary, bonus and restricted stock last year, plus more than $214,000 as a housing allowance and more than $68,000 for personal travel on corporate aircraft, according to documents filed with the Securities and Exchange Commission.

A lawsuit filed by Spitzer in October against Marsh alleged that the New York-based brokerage conspired with Ace and other insurers to rig insurance bids for corporate customers. An Ace assistant vice president, Patricia Abrams, pleaded guilty in New York state court to a misdemeanor criminal complaint alleging that she attempted to restrain trade. She was charged with providing noncompetitive "b" quotes intended to fool insurance customers under a "rigged bidding process." Abrams is expected to cooperate with Spitzer in his criminal investigation of the industry, according to a person familiar with the matter who spoke on condition of anonymity because of the ongoing investigations.

A lawyer for Abrams did not return a telephone call.

Ace was not named as a defendant in the suit, although the suit said Ace and other companies "conspired unreasonably to restrain trade." Marsh settled its portion of the suit in January, apologizing and setting up an $850 million compensation fund.

In January, the head of Ace's U.S. unit, Susan Rivera, resigned after an e-mail to her was included in court papers as part of Spitzer's investigation. In the e-mail, Geoffrey G. Gregory, the president of Ace's casualty risk unit, warns that "b" quotes could "potentially be construed as simply providing the appearance of competition."

Rivera was also mentioned in a settlement agreement signed in April by Spitzer and Willis Group Holdings Ltd., another New York brokerage. Spitzer alleged that a former Willis official "personally convinced" Rivera to send him "fraudulent e-mails" to justify a $500,000 payment from Ace to Willis. The payment was a "contingent commission" intended to prod Willis to steer corporate clients to "favored" insurance companies, Spitzer alleged. A Willis spokesman declined to comment; the company paid $50 million to settle the investigation without a lawsuit being filed. Barry Ostrager, a lawyer for Rivera, said his client did nothing wrong and that the Spitzer allegations are a "mischaracterization of the historical facts."

Rivera had been recruited to Ace by Evan Greenberg, according to a person familiar with the matter who requested anonymity because of the ongoing investigation. Ace announced in November that it had fired Abrams and Gregory, and, last month, a third executive. A lawyer for Gregory declined to comment.

In the conference call with investors, Evan Greenberg said the company's problems in bid-rigging had been mostly confined to the excess casualty unit, plus "a few" examples of behavior that were "inconsistent" with the company's code of conduct.

Greenberg also acknowledged the fraught regulatory environment. Asked whether he expected regulators to show increased "vigilance" from now on, he said: "I don't know that there'll be any more vigilance than we have today. It's a pretty frickin' vigilant environment."

Clockwise from top left, Jeffrey Greenberg, Maurice R. "Hank" Greenberg, and Evan G. Greenberg, who still heads Ace.