Brian Duperreault, who helped build a behemoth in Bermuda aschief executive officer of ACE Ltd. after over two decades at AIG,was tapped last week to help turn around another industrygiant–Marsh and McLennan Companies Inc.

New York-based MMC said Mr. Duperreault's appointment aspresident and CEO was immediate. He left his post as a member ofthe board at ACE to join MMC.

News that Mr. Duperreault would be leading the troubled MMC wasroundly applauded by analysts, who have been highly critical of themanagement of his predecessor as CEO, Michael G. Cherkasky.

“While he does not have insurance brokerage experience, hiscareer at ACE and AIG should serve him well in this new role,”wrote David Small, a financial analyst with Bear Stearns.

Alain Karaoglan, an analyst with Bank of America, called thehiring “a significant positive” because of Mr. Duperreault's“immense experience in the [property-casualty] insurance arena” andhis role at ACE.

“We think it was very important for MMC to bring in somebodyfrom outside their organization,” said Greg Dickerson, a directorwith Fitch Rating Services in New York. “In Brian Duperreault theyhave brought in somebody with a very strong track record who willprovide the benefit of an outsider's perspective on the challengesthat Marsh faces. He also brings industry expertise and therelationships in place to help him hit the ground running withouttaking too long to get up to speed.”

Mr. Dickerson said that his years at ACE give Mr. Duperreaultplenty of understanding about the value of insurance brokers. Headded that there is plenty of experience at Marsh now, with thehiring of Daniel S. Glaser in December as its chairman and CEO.

William Wilt, an analyst with Morgan Stanley, wrote that Mr.Duperreault “faces many challenges…but opportunities aresubstantial. During his 10 years as CEO of ACE, Mr. Duperreaultbuilt an extraordinarily strong international insuranceorganization. In time, we think it reasonable to expect the new CEOcan stabilize MMC's loss of brokerage market share and replenishits depleted human capital.”

“We frankly cannot imagine a better choice for the company,”wrote Meyer Shields, an analyst with Stifel Nicolaus. He said Mr.Duperreault can address MMC's ongoing weaknesses at Marsh,“including weak revenue growth, poor margin performance and lowemployee morale.”

Mr. Shields said Mr. Duperreault should be able to address theseissues by attracting “significant talent” to the company, andpredicted he will enjoy “greater success in winning higher revenuelevels from both clients and insurance carriers.”

All the analysts said they felt the hiring of Mr. Duperreaultwould cease any speculation that MMC would be acquired by Willis oranyone else. Rumors about a possible sale resurfaced recently.

Fitch's Mr. Dickerson said he did not think the sale of MMC wasan option, noting he is “somewhat skeptical that [Mr. Duperreault]would come out of retirement to dress up MMC for sale. But Iwouldn't rule out divestiture of certain business units once he hashad a chance to set his strategic vision for the company.”

Mr. Karaoglan said a takeover was less likely in the short term,with the MMC board making moves that indicate it wants to addressthe problems at Marsh. “We expect the revival of the insurancebrokerage unit to be a major focus of management in the comingquarters,” he said.

“It is too early to tell whether Mr. Duperreault will keep orsell the non-insurance components of MMC,” said Mr. Shields.

“We suspect this news takes some of the M&A speculation outof MMC shares, as it is unlikely Mr. Duperreault came aboard tosplit up the company,” Mr. Small agreed.

MMC has been in crisis since 2004, when its key insurancebrokerage unit–Marsh Inc.–was entangled in a scandal over itsplacement practices. That led to the resignation of MMC's CEO atthe time, Jeffrey Greenberg, and resulted in the firm agreeing togive up lucrative contingent commissions that investigators saidserved as kickbacks in a price-fixing scheme.

Mr. Cherkasky took over Mr. Greenberg's post, negotiating asettlement with New York's attorney general at the time (nowgovernor), Eliot Spitzer. The two had worked together asprosecutors earlier in their careers.

The brokerage's struggle to recover hit a low point lastSeptember when Marsh CEO Brian Storms was forced out of his postdue to disappointing results during his tenure. To replace him, Mr.Cherkasky named Daniel S. Glaser–who began his career at Marsh,before moving on to senior positions at Willis and AIG.

MMC Chairman Stephen R. Hardis hailed the new CEO's arrival.“Throughout his career, including 10 years as a CEO, BrianDuperreault has proven his ability to produce results and createshareholder value. We are delighted to welcome him to MMC,” he saidin a statement.

“I am honored to become the CEO of MMC, a company that comprisesseveral of the world's greatest brands in risk and insuranceservices and consulting,” said Mr. Duperreault, in the same companystatement. “I look forward to working with the company's talentedexecutives.”

He added that MMC is “an institution with unrivaled resourcesand capabilities. My mission is to capitalize on the strength ofMMC's operating companies to deliver value to clients, employeesand shareholders.”

From 1994 to 2004, Mr. Duperreault served as CEO of ACE Ltd.,the Bermuda-based insurer MMC helped found in 1985. He served asACE chairman from 2004 to 2007. ACE's net premiums are currently$12 billion.

Describing Mr. Duperreault's tenure at ACE, MMC said he hadgrown the firm “from a boutique catastrophe insurance specialistinto a global multiline commercial enterprise. He presided oversignificant organic growth as well as the acquisition of severalbusinesses, including the 1999 acquisition of Cigna's property andcasualty business.”

Under Mr. Duperreault, ACE's market capitalization grew from$1.1 billion to approximately $19 billion today.

Prior to ACE, Mr. Duperreault was with American InternationalGroup for more than 20 years, holding numerous positions,eventually becoming executive vice president of AIG Foreign GeneralInsurance and chairman and CEO of AIG's American InternationalUnderwriters, which comprises all of AIG's non-U.S. commercialbusiness.

Jeffrey Greenberg's brother, Evan Greenberg, ACE's chairman andCEO, issued a statement wishing Mr. Duperreault the best with hisjob at MMC, which he called “a great global franchise and animportant presence in our industry.”

He added that “we have every confidence that Brian will providethe same exceptional leadership to Marsh and McLennan that he gaveto ACE for so many years, and for which we will always be grateful.We look forward to working with Brian and all of his newcolleagues.”