Mr. Falk was named chief executive and president of the exchange in 2003.

But David E. King, chief executive of the exchange, staunchly defended its other idiosyncrasies as essential to London's success as a free and open market.

The exchange's board has 27 members, including Mr. Grasso and two other senior executives of the exchange.

Among the employees who would share in the 5 percent is John A. Thain, the chief executive of the exchange.

Mr. Sun resigned as chief executive of the exchange last November, saying he planned to emigrate to Canada.

There are 27 slots on the board: 12 from the securities industry, 12 who are called public directors and the 3 top executives of the exchange.

Mr. Thain also said that compensation for top executives of the exchange would be down 10 percent to 20 percent this year.

P. H. Ravi Kumar, chief executive of the exchange, which is based in Mumbai, said the deal would be announced on Friday.

Massimo Capuano, chief executive of the Italian exchange, says he may have the answer, announcing the plan on Tuesday.

The board would also appoint a chief regulatory officer, who would not report to the chief executive of the exchange.