BBC director-general Mark Thompson "intervened" to reverse Jeremy Clarkson's deal to record a voiceover for a Top Gear satnav, a report said.
Bosses at the organisation only found out about the plan, which was a breach of editorial policy, when they read about it in a newspaper.
Clarkson was potentially breaching his contract with the plan, which has seen more than 50,000 devices manufactured and many delivered to stores.
However, the BBC decided the deal with TomTom was not in accordance with policy preventing Top Gear's presenters endorsing motoring products.
Although the satnavs were sold, the broadcasting organisation's commercial arm, BBC Worldwide, made no profit from the deal as all proceeds went to Children In Need.
The BBC Trust's editorial standards committee (ESC) said the Worldwide arm failed to recognise the potential conflict of interest, saying the matter should have been referred immediately to BBC editorial policy. BBC chiefs came across the deal through an article on September 4 and Mr Thompson halted the deal on September 29, said the ESC report.
Copyright Press Association 2012