Blair's company is called Tony Blair Associated (TBA), and was launched after he resigned as prime minister in 2007. It has been granted approval to offer financial services.
The company promised "strategic advice on both a commercial and pro-bono basis, on political and economic trends and government reforms".
However, Blair's office denied any such plan, and described as "fatuous" media reports that he was starting a bank for the super-rich.
His spokesman said: "It is absurd to suggest the super-rich are now turning to Mr Blair for financial advice".
Blair, whose memoirs are to be published on September 1, has reportedly turned his consultancy into a big money-spinner.