Today's announcement that Willis Group Chairman and Chief ExecutiveOfficer Joe Plumeri will be stepping down does not come as a shockto financial analysts, but one analyst says the announcedreplacement did come as a surprise, and disappointed investors.

Meyer Shields, an analyst with Stifel Nicolaus, points out thatPlumeri's contract was set to expire next year. “It is far from abig surprise,” he says.

A spokesperson for Willis confirmed that the board has beenengaged in a search for a replacement for Plumeri for the pastyear, but the search was not made public

Willis announced today that Plumeri will be replaced by McKinsey& Company Senior Partner Dominic Casserley, who has spent 29years at the consulting firm working on financial services.

Shields says he was surprised that the Willis board decided tohire someone from outside the insurance-brokerage industry,especially someone who is not well known in the insurancecommunity.

“He is not on the top of anyone's list of most likelysuccessors,” says Shields.

Greg Dickerson, director in the insurance group for FitchRatings, says part of the reason the board may have gone outside isbecause it was “looking for a fresh set of eyes” from outside theindustry.

Pointing to “obvious parallels” between Casserley and Aon'shiring of Greg Case in 2005—who also came from McKinsey—Dickersonsays the hire is aimed at addressing a myriad of issues dealingwith how to expand Willis' revenues in the face of an insurancemarketplace that remains challenging in terms of limited growthpossibilities.

“Willis may be looking for someone new, with a set ofnon-traditional ideas,” says Dickerson.

Notes Shields, “When looking at the issues there, McKinseyalumni have a pretty good track record of turning around companiesthat have gotten a little off track, and Willis has gotten a littleoff track.”

The Willis spokesperson says the board “chose the bestcandidate” and believes “it will have a solid partnership andstrong leadership” in Casserley, Plumeri, who will remain asnon-executive chairman through July 2013, and Steve Hearn, 46, whowill become deputy CEO of Willis Group.

On the news of Casserley's appointment, Willis' stock fell 50cents, or 1.35 percent, by mid-morning to $36.40 a share. It closedon the day down 48 cents, or 1.3 percent, at $36.42.

Shields says the slide may have had more to do withdisappointment among investors who bought into rumors that the firmwould sell itself. The hiring of Casserley, Shields says, onlyconfirmed the board's intent that the broker will remainindependent.

“Right now, one can infer [from the hiring of Casserley] thatWillis is not for sale,” says Shields. “Hiring a consultant meansthat there is something wrong, but to be fair, when you look at theHanover Group or Aon, [which] were taken over by McKinsey guys, theturnaround was successful.”

This story was updated at 4:11 p.m. EDT with stockinformation.