The two sports, which were last played at the 2008 Beijing Games, each failed in separate attempts to win reinstatement for the 2012 and 2016 Olympics.
The heads of the two governing bodies said Saturday they plan to unite into the International Baseball and Softball Federation in hopes of increasing their chances of coming back for the 2020 Games.
A major obstacle still stands in the way — getting major league baseball stars to play.
"Without that, we'll have an uphill battle," International Softball Federation President Don Porter told The Associated Press.
Porter and International Baseball Federation counterpart Riccardo Fraccari submitted their merger plans to the International Olympic Committee, which approved the idea in principle but will continue to review it.
The proposal calls for men's baseball and women's softball to be played at a single venue over seven to 10 days. Each tournament would feature eight teams. Baseball and softball would be two disciplines under a single sports banner.
The merger still requires formal approval from the congress of both federations.
Porter said the combined federation would operate only for the Olympics, a plan that was questioned by IOC executive board member Denis Oswald.
"That's not enough," Oswald, who heads the Association of Summer International Sports Federations, told the AP. "They should be one federation overall. We didn't say to merge just for the Olympics."
Baseball and softball were voted off the Olympic program by the IOC in 2005, making their last appearance in Beijing. Softball had been in the Olympics since 1996, and baseball since 1992.
Softball and baseball are competing with karate, roller sports, squash, sports climbing, wakeboard and wushu for inclusion in 2020. Only one spot on the Olympic program is open.
The IOC executive board will decide next May which sport to recommend for inclusion. The final decision will be made in a vote of the full IOC in Buenos Aires in September 2013.
The absence of major league players in the Olympics was a major factor in the IOC's decision to drop baseball, and the issue remains crucial to any chance of reinstatement. Major League Baseball has been unwilling to shut down the season during the Olympics.
"If they don't propose their best athletes it will be difficult," Oswald said. "If they do, then they have a chance just like the others."
Porter and Fraccari said they have scheduled a meeting with MLB officials in New York on Aug. 1 to seek a solution.
"Most people tell me that without commitment from MLB, it's not going to work," Porter said. "It would certainly strengthen our bid if the MLB says they will commit their players."
Pro baseball leagues in Japan, Taiwan, South Korea and Australia are committed to taking part.
"We have to be realistic about how MLB can release their players," Fraccari said.
The Italian proposes a shortened Olympic tournament that could be completed in five or six days, making it easier for major leaguers to play. He also raised the possibility they could be released to play just for the semifinals and final.
"I think we are moving in the right direction," Fraccari said.
Porter had previously rejected offers to join forces with baseball but now sees it as necessary.
"Our preference would have been to stay separate, but we want to be back on the program and we need to find the best way to do it," Porter said. "We've got a good opportunity here. The easy thing would be to give up. For this, we've got to keep trying."
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