Shareholders have called for a break-up of Marsh & McLennan, the financial services company that owns Mercer Human Resource Consulting and Putnam Investments, as its share price fell to $25 last week.

Several of the group's largest shareholders believe there is no reason for it to remain as one company. They are critical of the performance of chief executive Michael Cherkasky, who was promoted from Kroll, a subsidiary, in 2004 when his predecessor Jeffrey Greenberg left. The share price's low had not been reached since October 2004 when New York state attorney general Eliot Spitzer filed a bid-rigging lawsuit against the group that led to Greenberg's resignation. At this level, shareholders and analysts argue the sum of its parts exceeds the total. A top-10 shareholder said: "There aren't any reasons why the business should remain intact. They are complicated businesses and they could be run more efficiently individually." Marsh & McLennan conducted a review of Putnam Investments last year but concluded it would keep the company. Cherkasky acknowledged there were no synergies in owning Putnam as it had no cross-over with clients in other business lines. A source said Mercer held talks with IBM, the information technology provider, last year but a deal failed when they could not agree on price. Analysts asked Cherkasky at the publication of the group's earnings this month to quantify the impact of cross-selling on revenues, which is the argument the group makes for keeping the business together. Cherkasky said: "I am embarrassed to say we can't. We don't have the systems that allow us to do that efficiently. It's mostly by stories and getting examples about this." Large shareholders, which are some of the biggest US mutual funds, are also critical of the board. One said: "The board has to be publicly embarrassed. They promoted a guy who appears to be in over his head." Cherkasky and Spitzer worked at the Manhattan district attorney's office in the early 1990s. One shareholder said mutual funds would want to avoid landing on Spitzer's radar screen and, as a result, may have been less active on the issue. US fund manager Capital Group is Marsh & McLennan's largest shareholder with a 12.1% stake, T Rowe Price has 8.3%, Barclays Global Investors 3.1%, Van Kampen Investments 2.8% and State Street Global Advisors has 2.6%, according to Citywatch Global, a shareholder register.