It said in February that it was studying a spinoff of the tobacco unit to a limited partnership.
William Murray, Philip Morris's new chairman, said that his "first message is that all of our businesses are performing well, particularly our two tobacco units."
Separating the tobacco unit would give it a higher value in the marketplace, the company believes.
Splitting the international tobacco units from the domestic operations could give investors a purer play in the rapidly growing international market, some analysts said.
The deal, in which B.A.T.'s tobacco unit is to be spun off, would create one of the world's biggest financial companies.
Mr. Icahn has criticized management, particularly for its decision to sell the tobacco units and retain the cookie and cracker business.
At the tobacco unit, Mr. Johnston will succeed Ralph Angiuoli, who is retiring.
The tobacco unit, which has been losing market share, experienced a blow with the failure of Premier, its "smokeless" cigarette.
The tobacco unit said that the added 2,900 job cuts would come in Russia and other countries of the former Soviet Union.
Even yesterday's sale and subsequent spinoff of the domestic tobacco unit, guarantees bankers fat paychecks for months to come.