The investment bank Wasserstein Perella has dropped out of its role of lead adviser to Britt Allcroft, the media group which owns the rights to children's television characters Thomas the Tank Engine and Sooty.

Wasserstein had been brought in earlier this year after a £225m (E364.5m) bid by Hit Entertainment, and was billed as a big-hitting financial adviser which would be able to secure Britt a major deal.