The Sunday announcement came hours after Hollinger officials removed Black as chairman and said they would be suing the former media
The brothers said they would launch a $326.5 million offer to buy Toronto-based Hollinger Inc which controls about three-quarters of the voting stock of Hollinger International, owner of London's Daily and Sunday Telegraph and the Chicago Sun-Times newspapers.
The bid would also take on about $140 million in debt.
Hollinger International, which also owns the Jerusalem Post newspaper, said in a brief statement that the company and its board "intend to review the offer for Hollinger Inc. and its implications for Hollinger International."
The deal faces steep legal hurdles for embattled press baron Black, who stepped down as Hollinger International chief executive last year after $32 million in unauthorised payments were discovered. He was fired as chairman on Saturday.
Black, who was due to submit $850,000 to Hollinger International on Sunday under an agreement over the unauthorised payments, was not available for comment.
Black owns 78% of Hollinger Inc through his privately held company Ravelston, a stake he has agreed to sell to the secretive Barclays, who operate from the tiny island of Brechou, which they own, off the northwest coast of France.
Black is being sued by his former
company for mishandling funds
Diverse business holdings
Their business empire spans a wide range of interests including London's luxury Ritz Hotel and Littlewoods, Britain's second-biggest mail-order business and high street store chain.
The US Securities and Exchange Commission filed a legal case on Friday attempting to block Black from selling his stake while dual investigations by the SEC and a special committee of the Hollinger International board were underway.
Hollinger International filed its own $200 million legal case on Saturday against Black, former executive David Radler, Hollinger Inc and Ravelston, with allegations ranging from excessive management fees paid to Ravelston to the altering of company documents.
Canadian-born Black, a member of Britain's House of Lords, built Hollinger International into the world's third-largest newspaper empire. He has repeatedly denied any wrongdoing.
The tycoon, fascinated by Napoleon and author of a biography of Franklin D Roosevelt, has a reputation for imperiousness due to his manner with shareholders, the press and high-profile enemies such as former Canadian Prime Minister Jean Chretien.
Unchanged editoral stance
George Jones, political editor of the right-wing Daily Telegraph, said he did not think a takeover by the Barclay brothers would affect the editorial stance of the newspaper.
"I would have thought (the Barclay brothers) are broadly of the conservative mind of businessmen," he told BBC television. "I think they will continue the political direction."
A spokesman for the Barclays said a takeover would benefit Hollinger International shareholders.
"After, let's face it, a real period of uncertainty and concern, they think this is a very good offer, and this is actually a very good move for Hollinger International," spokesman Tim Payne told Reuters.
"It will bring some stability back to the company."
The spokesman said the Barclays were "willing to listen" to the recommendations of investment bank Lazard, which is carrying out a strategic review of the Hollinger International assets.