Last Friday evening a train was derailed on the Piccadilly Line between Hammersmith and Baron's Court. The section of track involved was maintained by Metronet. The accident is believed to have been caused by a broken rail.
On Sunday morning, 14 passengers were injured when a train was derailed on the Northern Line at Camden Town station. Tube Lines said no problems had been found during an inspection of the track the previous evening.
Shares in Jarvis, a member of the Tube Lines consortium, ended 11p down at 290p on Monday.