The SEC-EDGAR filing specifies that Mr. Greenberg has purchased 300,000 Marsh shares at $14.4791 each, 120,000 shares at $15.8437 each and 120,000 shares at $20.6354 each, altogether at a cost of $8.72 million. At the current stock-market value at the New York Stock Exchange he can now turn around and sell for a profit of $6.78 million. (The filing can be found at )

Vested stock options refer to granting the right to senior executives to purchase a certain amount of company shares at a fixed price in the future, usually a period of at least one to four years down the road.

It's a corporate-governance strategy commonly used by corporate boards of directors to align the interest of executives and ordinary shareholders, by encouraging executives to focus on boosting the company share price on the stock market.

Currently, the shares of Marsh & McLennan are trading at around $28.70 on the stock market, or about $15.5 million for 540,000 shares Mr. Greenberg has acquired. That means since Mr. Greenberg has exercised his vested stock options for 540,000 shares at a previously-agreed upon cost of $8.72 million, he can profit the difference, which comes to $6.78 million at the current NYSE value.

Paul Hodgson, senior research associate at Portland, Maine-based Corporate Library, an independent investment-research firm providing corporate-governance data, said that Mr. Greenberg's stock-option benefits are along the lines of what one could expect for the CEO of a major financial company. "This is a pretty ordinary amount when compared to what are offered in the marketplace," Mr. Hodgson told National Underwriter.