(FORTUNE Magazine) – You figure it out. Charles Hugel, 59, is chief executive of Combustion Engineering. RJR Nabisco has its own President F. Ross Johnson, 56. RJR Nabisco's chairman, J. Paul Sticht, is retiring. So why did the RJR Nabisco board vote for Hugel, instead of Johnson, to succeed Sticht, in the rare capacity of ''non-executive'' chairman? Johnson headed Nabisco when it merged with R.J. Reynolds, and some of his moves have burned up tobacco types. There has been speculation that Hugel, a neutral board member, was chosen to allow time for the smoke to clear. But the new chairman insists otherwise: ''There is no cookie vs. cigarette war going on over there. The fact is, there is nothing more to this than meets the eye.'' What meets the eye is unprecedented in the U.S.: the CEO of a major corporation serving as chairman of another. Says former Celanese chairman John Macomber, an RJR Nabisco director: ''It is an atypical and bold appointment. But that's not unusual for Ross. It was his idea. It will help him deal with his outside constituencies and divide up the load.'' One financial analyst thinks the arrangement has merit. Says Larry Adelman, senior vice president of Dean Witter: ''If the chairman is not operating in the company, then he represents the shareholders more truly.''