His Mayfair-based company has recruited senior financiers and has been authorised by the FSA, the Sunday Times reveals.
Since leaving office in 2007, Blair has amassed a fortune estimated to be in excess of £20m. When he first launched the Tony Blair Associates (TBA) consultancy business, Blair said it would provide advice on political and economic trends and government reforms. It has provided advice to the Kuwait Government and to the Mubadala sovereign wealth fund.
TBA is now able to offer a range of financial services to clients. Blair's investment firm is just one of a string of companies - each called Windrush or Firerush - he created after leaving No 10.
One of these companies, Firerush Ventures No. 3, was registered with the FSA in January this year. The paper says documents show it can offer financial services to clients and will trade under TBA.
The FSA documents state TBA can "arrange deals in investments" for clients - including shares, unit trusts and government securities.
Some of Blair's key staff have registered with the FSA for Firerush, including former chief of staff Jonathan Powell, who is a managing director at Morgan Stanley.
Blair's office also recruited Mark Labovitch last month to be chief operating officer at Firerush. He previously worked at Dresdner Kleinwort, LongAcre Partners and at Mesa Global. According to the FSA documents, another recruit is Varun Chandra, who previously worked in mergers and acquisitions for Lehman Brothers.
Firerush is authorised to trade across Europe, including Luxembourg, Liechtenstein and Gibraltar.
Blair's private sector work to date has mainly been in the financial sector, including advisory roles with JPMorgan and Zurich.