The Reuters news service is poised to sign a deal with London Transport to sponsor a network of electronic business boards showing up-to-date share prices and stock market information in Underground stations.
Reuters marketing and communications manager Adrian Duffield confirms the service has been in negotiations with LT.
But Duffield says it is too early to make any announcement.
Representatives of the Tower of London are also holding talks with LT to have the Tower Hill Underground station renamed Tower of London.
A spokeswoman from the Tower of London says the tourist attraction, which is run by Historic Royal Palaces, is regularly approached with sponsorship ideas.
She refuses to confirm the nature of the talks taking place with LT and denies there is any imminent plan to change the name of the Tower Hill Underground station.
LT has only struck one deal since announcing that every Underground station was available for sponsorship last year.
United Airlines sponsors an Underground train on the Piccadilly Line to Heathrow.
LT says that it has looked at a number of “commercial op-portunities” in the past year, but will not confirm any businesses involved in sponsorship negotiations on the Underground.