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 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.
BBC Sport understands the Ricketts group bid also includes US hedge fund entrepreneur Ken Griffin.
A statement on Wednesday from the Ricketts, who have had a majority interest in the Cubs since 2009, said they would share further details “in due course”.
“The Ricketts Family, owners of the Chicago Cubs, can confirm they will be leading an investment group that will make a formal bid for Chelsea this Friday,” the statement read.
“As long-time operators of an iconic professional sports team, the Ricketts Family and their partners understand the importance of investing for success on the pitch, while respecting the traditions of the club, the fans and the community.”
The bid is described as “very serious” by one insider, with the family understood to have already done due diligence when they previously enquired about buying the club in 2018.
Broughton, who announced his intention to buy Chelsea over the weekend, told the BBC “I am absolutely delighted to welcome Lord Coe to our bid. His reputation speaks for itself, and he will bring phenomenal insight, leadership, and sporting knowledge to Chelsea Football Club.”
His group is expected to submit a bid in the next 48 hours.
Coe said he was “certain that Sir Martin is the right man to lead Chelsea Football Club into its next chapter” citing his “exceptional track record in British business”.
Coe added “most importantly, like me, he is a lifelong Chelsea supporter and Shed End season ticket holder. I know that this bid is for the millions of Chelsea fans around the world. We love our club and will always put the fans first”.
Broughton, 74, is a former British Airways chairman and now chairs private investment firm Sports Investment Partners. He was briefly Liverpool chairman in 2010.
Those close to the consortium declined to tell BBC Sport who was financing the bid or who else was involved.
Coe would take a seat on the Chelsea board if Broughton’s bid is successful, according to the PA news agency.
More than 20 credible parties are interested in buying the Premier League club.
British businessman Nick Candy said earlier this month he was exploring “a number of options for a potential bid”.
Former Chelsea striker Gianluca Vialli announced on Wednesday that he is working with Candy on his bid.
Vialli co-owns Tifosi, a mergers and acquisitions company for the football sector.
The former Italian international said: “I am proud and feel very privileged to support Mr Candy’s bid to buy Chelsea Football Club.”
The 57-year-old added: “We share the same view that if the bid is successful, we will try to be the best possible custodians of the club, knowing that it is imperative that supporter concerns are front and centre of any owner’s priorities.”
Only some of the interested parties or bidders have come forward so far:
Hansjorg Wyss and Todd Boehly
Swiss billionaire Hansjorg Wyss and US businessman Todd Boehly have formed part of a consortium to try to take over Chelsea.
Wyss told Swiss newspaper Blick that he had been offered the chance to buy the club.
The 86-year-old is worth an estimated £3.9bn.
Boehly, who is a part owner of Major League Baseball’s Los Angeles Dodgers, was previously linked with a takeover of Chelsea in 2019.
Turkish billionaire Muhsin Bayrak says he is one of those to have launched a bid to buy the club, adding “we will fly the Turkish flag in London soon”.
Bayrak is chairman of AB Grup Holding, which he founded in 1999, and has investments in crypto currency, construction, tourism and energy sectors.
Sources close to Bayrak told BBC Sport he is determined to buy Chelsea and his lawyer was set to be in London for talks last week.
British billionaire Jim Ratcliffe, who owns Ineos and bought French club Nice in 2019, has previously shown interest, but will not seek to purchase Chelsea because he does not see it as good value.
The Ricketts family bought the Cubs in 2009 and renovated their Wrigley Field stadium as part of a push to create a winning team.
The Cubs won the World Series title in 2016, ending a 108-year wait and the longest title drought in the game.
It was estimated five million people attended the Cubs’ victory parade in Chicago.
Thomas Ricketts is chairman of the Cubs, while his siblings also sit on the board.
The family also own a 25% stake in American TV network CSN Chicago.
The American investment firm tasked with selling the club expects a sale could happen by the end of March following positive conversations with the UK government.
One issue the bid already faces is the patriarch of the family – 80-year-old Joe Ricketts – and influential figure in conservative US politics, had to apologise in 2019 for anti-Muslim comments he made in leaked emails.
A source close to the Ricketts camp told the BBC that Mr Ricketts would have no role or involvement in the bid for Chelsea, which is being headed up by his children Tom, Laura and Todd.
Russian Abramovich had his British assets, which includes Chelsea, frozen last week and was disqualified as a director of the club.
The Blues are allowed to continue operating after a special licence was issued by the UK government,
This also ensures Chelsea’s staff are paid and allows existing season ticket holders to attend matches, but a new licence will need to be issued for the club to be sold.
Abramovich has owned Chelsea since 2003, with the club winning 21 trophies during his tenure.
Meanwhile, Uefa is seeking clarification from the European Union on future Champions League matches involving Chelsea.
Abramovich was sanctioned by the EU on Tuesday.
Wednesday’s last-16 tie against Lille in France, where the Blues hold a 2-0 advantage, went ahead.
Thomas Tuchel’s side are the current holders of the Champions League trophy after they beat Manchester City 1-0 in last year’s final.
“Uefa is fully committed to always implementing relevant EU and international sanctions,” Uefa said.
“Our understanding is that the present case is assessed in the context of the licence issued in the UK which allows Chelsea FC to continue minimum football activity whilst providing a safeguard that no financial gain will result for Mr Abramovich.
“We will work with the EU and relevant member states to ensure we have full clarity and remain in lockstep with all relevant and applicable measures in line with latest developments.”
Meanwhile, Chelsea will avoid a 10-hour round trip by bus for their FA Cup tie at Middlesbrough on Saturday after the government increased its cap for away travel as part of the club’s operating licence.
The cap was set at £20,000 after Abramovich was sanctioned, as part of a set of conditions to allow the club to run day-to-day.
But the increase will allow the team to fly to the North East for the quarter-final tie.
Chelsea’s players and staff flew to Lille for Wednesday’s Champions League tie because it was already arranged prior to the sanctions.
A Chelsea spokesman said: “We are grateful for the government’s continued attention to our requests for amendments to the licence.”
The government has already increased spending for home matches from £500,000 to £900,000, with talks continuing over ticket, retail and merchandise revenue.