Shares in train and bus firm Go-Ahead Group have fallen as much as 17% after the release of half-year results (link below.)
http://news.bbc.co.uk/1/hi/business/7246564.stm

Profit before tax fell 3.6% to £45.2m in the final six months of 2007, which was better than expected.

But in the rail business, it warned that lower subsidies and higher profit share would lead to annual operating profits below that of last year.