A club official said Tuesday that Dan Adler and Adam Levin reneged on the deal by failing to transfer $400,000 to pay off debts as agreed.
A lawyer for Beitar owner Arcadi Gaydamak says his client is considering suing them for breach of contract.
Beitar announced last month that Adler and Levin had signed a contract to take full financial responsibility for the club. The pair visited the team's training ground and posed for photos with players.
"Now I am obliged to stay," Gaydamak told Radio Tel Aviv on Monday. "I looked for a responsible new owner who will take care of the team and provide all the support, but till now nobody showed true intentions to provide support for the team."
Levin is a managing director of private equity fund Criterion Capital Partners and chief executive of social media company Bebo. Adler is the founder of Media Eagles, a consulting firm in California.
In an effort to raise funds, Beitar agreed a deal to sell striker Chen Azriel to Maccabi Haifa on Sunday for a fee of about $1 million.
Formed in 1936, Beitar is one of Israel's most popular and successful teams. It enjoyed its best period following Gaydamak's purchase of the club in 2005, highlighted by winning the league and cup double in 2008.
But when Gaydamak left the country while battling financial scandals in Israel and Europe, he cut funding to the team and it fell on hard times. It finished in 11th place last season, narrowly avoiding relegation.
The team has also attracted controversy for the behavior of its fans, who are notorious for racist chants and taunting Arab players on opposing teams.
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