Neither sport is included at this year's London Games and they must wait until 2013 for an International Olympic Committee (IOC) vote on the inclusion of new sports in 2020.
Baseball and softball are competing with karate, roller sports, sports climbing, squash, wakeboard and the martial art of wushu for a spot in the 2020 Games. A final list will be put to the vote in September 2013 for one berth.
"IBAF and ISF are still exchanging drafts of the Memorandum of Understanding but we hope to have a working draft finalised in time for an April 19 meeting we have with the IOC," IBAF president Riccardo Fraccari said.
He added that while the joint bid would mean they would be included in the Games programme as one sport if picked, the two federations would stay separate.
"Both federations would continue to operate as they always have, that is to say independently, in overseeing their respective sports and events," said Fraccari.
"Any official cooperation between our institutions and the associated activities would be expressly for a return on to the Olympic programme."
The London Olympics starting on July 27 will have 26 sports while the 2016 Rio de Janeiro Games will have 28, after golf and rugby were included in a 2009 vote.
"For the athletes there is no doubt it is their ultimate goal to play in the Olympics and become Olympic athletes so any undertaking to help realise this is welcomed," said Fraccari.
"Overall the consensus of a combined approach has been positive as we have used this time off the programme to review our direction and strengthen key areas that I feel brings us closer to the Olympic Movement."
Baseball and softball became the first sports since 1936 to be cut from the Games after they were dropped in a 2005 vote.