The share price fall has seen the value of Asciano managing director Mark Rowsthorn's 10.8 per cent stake fall from over $700 million to $49 million. The Citi note warned the group would struggle to service its debts and would come within a whisker of breaching its debt covenants in 2009-10. It also warned Asciano could be forced to writedown part of the $4.2 billion of intangible assets on its balance sheet. Citigroup said Asciano's problems had been compounded by the recent fall in asset values for port and rail assets worldwide.