London Mayor Boris Johnson has been accused of giving Barclays Bank £10m of free advertising after it pulled out of sponsoring his bike hire scheme.
Transport for London was expecting Barclays to contribute the sum as part of an expansion into the south west London suburbs.
Documents released by Transport for London under a Freedom of Information request show a "Heads of Terms" agreement was being negotiated in August.
In December the bank announced it was withdrawing it was withdrawing its sponsorship of "Boris Bikes".
But the expansion went ahead with 2,000 extra bikes branded with the Barclay's logo.
Three London boroughs - Hammersmith & Fulham, Lambeth and Wandsworth -were asked to contribute more than £4m.
The £10m shortfall is believed to have been met from TfL's budget.
London Assembly Labour spokesman Val Shawcross said: