The Ricketts family, who own Major League Baseball team the Chicago Cubs, and a consortium featuring Lord Coe both intend to make a bid for Chelsea by Friday's deadline.
The Ricketts said they are are leading a bid from a group of investors.
London Olympics chief Coe has joined ex-Liverpool chairman Sir Martin Broughton's bid.
Roman Abramovich's attempt to sell the club has been halted after he was sanctioned by the UK government.
That move came in the wake of Russia's invasion of Ukraine, with Abramovich understood to have strong ties to Russian president Vladimir Putin.