Mumbai: The Reserve Bank of India (RBI) has warned that banks will not be able to sustain infrastructure financing as their long-term loans have already increased to almost 40 per cent from less than 20 per cent five years ago.

This has left limited space for banks with shorter-term sources of funds to increase their long-term exposure, the RBI said in its ''Report on Currency and Finance - 2005-06.''

Medium-term and long-term loans had a combined share of 47.6 per cent in banks'' loan portfolio at the end of March 2005 against 17.5 per cent at the end of March 1995, the RBI report said.

Total bank lending to the infrastructure sector at the end of March 2006 stood at Rs108,787 crore, up 37.7 per cent from a year earlier.

Power accounts for more than half the loans to infrastructure and telecommunications, roads and ports.

Over 50 per cent of the term deposits mobilised by banks in 2007 had tenures of less than one year, compared to around 30 per cent in 2000.

This will aggravate the asset-liability mismatch for banks. The RBI said inadequate long-term resources could affect India''s growth, especially infrastructure development, the report warned.