Transport for London was today told to "tighten up" its approach to agreeing sponsorship deals.
Labour Assembly member John Biggs gave the example of a £36 million deal with Emirates airline to sponsor Boris Johnson's new Thames cable car. As part of the deal, the airline gets its branding on all Tube maps.
Mr Biggs said: "So far TfL seems to have taken an ad hoc approach to sponsorship, which could expose it to unnecessary risk if a sponsor suffered serious reputational damage."
In a report today Mr Biggs calls on TfL to conduct deals in the open.
TfL last year extended its cycle hire deal with Barclays to 2018 for £25 million.
The report says: "TfL has not demonstrated why this was better than going back to the open market."
Graeme Craig, TfL's commercial development director said: "We welcome this report, which works with the grain of how we are developing our new sponsorship policy."
