The IOC executive board is considering a recommendation to remove the three for the 2008 Beijing Games.
Golf and rugby could join the Olympic program, provided the top athletes in each take part. A third, the Chinese martial art wushu, also is under consideration.
If the executive board approves the proposals, the final decision will come at an IOC meeting in Mexico in November. Since the IOC refuses to increase the number of Olympic sports above the current level of 28, golf and rugby could be admitted only if others are dropped.
'I believe the proposal is a strong warning - a shot across the bows of these federations that we think there is a problem there,'' IOC president Jacques Rogge said.
A request to reinstate polo in 2008 was among those rejected Thursday. Thirteen other sports were turned down, including ballroom dancing, surfing, bowling, billiards, squash, water skiing and racquetball.
An IOC report said widespread participation in baseball and softball is limited to a handful of countries. The sports also require expensive and specific venues that would be white elephants in most countries after the Olympics, it says.
Modern pentathlon consists of fencing, swimming, shooting, horseback riding and running, and the report said participation was limited because of the expense.
Cutting sports requires a majority of the assembly of more than 120 IOC members. A two-thirds vote is needed for adding sports.
Aldo Notari, the Italian president of the International Baseball Federation, wants to meet with officials of the U.S. Olympic Committee, major League baseball, players' associations and pro leagues in Japan and other countries.
'All the baseball officials must work together to keep our sport on the program,'' he said.
Baseball became a full medal event in 1992. Olympic baseball has failed to include top major league players since the season overlaps with the games.
Joel Bouzou, secretary general of the modern pentathlon federation, said it would be a mistake to get rid a sport that was brought into the games by Pierre de Coubertin, the French founder of the modern Olympics.
'It's clear there will never be millions of pentathletes in the world,'' Bouzou said. 'But it is a symbolic sport and part of Pierre de Coubertin's legacy. If pentathlon is taken out of the program, it will die.''
Rogge said IOC members will have to consider the future of a sport if it is no longer part of the Olympics.
'We have to look at the sport's political aspects. Definitely it isn't going to be an easy task,'' he said.
The executive board agreed with the report that chess and bridge are ineligible for consideration even though they are recognized by the IOC because they entail no physical exertion.
The executive board has yet to act on other recommendations, including:
- exclusion of Greco-Roman or freestyle wrestling, citing 'low public and media comprehension of differences between the two disciplines.''
- a review of boxing because of image problems; a proposal that women's boxing not be considered for inclusion.
- elimination of canoe-kayak slalom, three-day event in equestrian, race walking in track and field, keelboat class in sailing, team synchronized swimming, lightweight rowing and badminton mixed doubles; a reduction in athletes and events in shooting.