One of the first questions put to Juan Antonio Samaranch, incoming president of the International Olympic Committee (IOC), following his election Wednesday was whether he planned to retain the forceful Monique Berlioux as executive director, the position she has held for nine years.

Samaranch appeared truly startled by the query, as if someone had asked whether he intended to go on breathing.

"Of course," he said after a brief, disbelieving pause. "Madame Berlioux is my right hand."

And perhaps three fingers of the left as well.

Berlioux, 54, is the power behind the throne -- although not always behind the scenes -- at the IOC, the lofty-minded but sometimes heavy-handed body that owns and controls the Olympic Games.

A tough but charming Frenchwoman with a fascinating background in sports (she was an Olympic swimmer), journalism (reporter, columnist, television producer and reporter), and administration (press officer in the de Gaulle government), she runs the business side of the IOC, supervising its full-time staff of 30 and administering an annual budget in excess of $3 million.

While the policies of the IOC are officially set by its 80-odd members -- who meet in full session once a year, and twice in Olympic years -- she has the responsibility of implementing them, and conducting the day-to-day operations of the most important organization in amateur sports.

An indefatigable worker whose biggest shortcoming is probably her reluctance to delegate authority, she is intimately familiar with every aspect of the IOC's affairs. She attends every session, every meeting of the executive board and other key committees, and probably knows more of what is happening in the Byzantine world of amateur sport than anyone else, including the IOC president.

She also knows IOC rules, procedures, protocol and history inside out.

'In my opinion, Monique runs the IOC. The president is a figurehead," said one U.S. television executive who has dealt with her extensively.

Others would dispute that assessment, pointing out that she is, after all, merely a salaried employe and theoretically not a policy-maker.The same is true of Pete Rozelle. In fact, Lord Killanin of Ireland, the IOC president since 1972 whose terms expires at the end of the Moscow Games Aug. 3, relied on her heavily.

Samranch is expected to lean on her even more.

"He's a good diplomat and will be fine at hosting ceremonial occasions, but he's wishy-washy when it comes to hard decisions," one IOC insider said of Samranch, the current Spanish ambassador the Soviet Union. "Monique will run the IOC completely now."

The Chateau de Vidy -- the Ioc's ornate, 18th-century headquarters on the shores of Lake Geneva in Lausanne, Switzerland, is Berlioux's castle. She can be found there, working, from dawn to dusk.

At IOC sessions, she is regularly thrown into the limelight because she is the organization's most visible spokesperson, giving daily press briefings. Her performance is often maddeningly masterful. She never volunteers anything controversial, but is adept at delivering terse barbs and evasive answers in both French and English to probing reporter's questions.

Since the IOC is a fiercely independent and haughty oligarchy that answers to no authority except its own charter, she often is put in the position of defending seemingly arbitrary and self-serving decisions.

This was the case at Lake Placid, N.Y. in Feburary, where she declared daily that the Moscow Olympics would go ahead as scheduled this summer despite the Soviet invasion of Afghanistan and the Carter Administration's calls for a boycott.

Consequently, Berlioux gets more than her share of "bad press", especially in America. Even the staid New Yorker magazine referred to her as "a lady with a smile like a shark."

But behind the austere exterior and sometimes biting manner is a rich vein of humor, gallic charm and savoir-faire.

A graduate to the Sorbonne in Paris, Berlioux came to the IOC in 1967 as director of press and public relations, and quickly moved up the ladder of a well-heeled, aristocratic organization that has never had a woman member.

She knew about amateur sport, having been a world class swimmer, and avid cyclist, equestrienne, basketball player and oarswomen. She held 40 French national swimming titles between 1938 and 1952, and was a semifinalist in the 1948 London Olympics.

As a journalist, she wrote for some of France's most respected newspapers, reporting from China and Algeria, and was a correspondant for a number of foreign papers.

She also reported on French radio and television, and produced and directed short films, a "Woman's Magazine," and other programs. In 1960, she moved to the French Ministry for Youth and Sport as head of the press department. She stayed at the ministry for seven years, then joined the IOC.