The new bids were revealed by Ownership Associates founder Christopher Mackin, who is an adviser to the Dow Jones employee union. Mackin's firm, which provides strategic and technical advice to groups exploring employee ownership, said the entrepreneur and the Wall Street group made contact with him but declined to give their names.
This news comes after Philadelphia Media Holdings stepped into the bidding war, saying it would compete with Rupert Murdoch's $5bn (£2.5bn) takeover bid, offered by News Corporation last month.
Brian Tierney, chief executive of Philadelphia Media Holdings, which owns the Philadelphia Inquirer and Philadelphia Daily News, said: "We don't believe News Corporation is overpaying.
"This is one of the greatest journalistic enterprises ever created. If there is a process for the sale of the business, we would be inclined to participate in partnership with others."
Earlier this week, US retail billionaire Ron Burkle stated he was considering making a bid to buy Dow Jones, after the Wall Street Journal employees' union contacted him with an appeal to block Murdoch.
Burkle recently unsuccessfully tried to buy the Tribune Company, which publishes the Los Angeles Times and the Chicago Tribune. He is the owner of a $2.5bn fortune, made in the supermarket business.
News Corp submitted its unsolicited bid in early May, which valued Dow Jones at $5bn, or $60 a share, which represented a 67% premium.
The bid was rejected by the Bancroft family, which controls 64.2% of the voting shares, but the family met Murdoch last week to discuss the offer. Murdoch said preliminary talks were "constructive".
Some Bancroft family members said that they refuse to sell the company to Murdoch at any price, concerned that a News Corp takeover would "crush quality and independence" at the journal.
Shares of Dow Jones fell 16 cents to $60 yesterday. They have risen 65% since News Corp.'s bid became public.