NEW DELHI (REUTERS) - India's railway budget, to be presented later on Thursday, will signal the direction of long-term reforms needed to revamp the world's fourth-largest rail network, its minister said.

"The budget will set the direction of long and difficult road of reform," Mr Suresh Prabhu told state-run broadcaster DD News ahead of his budget presentation.

India's decrepit state-run train services stand to receive at least a 25 per cent boost in investment to over US$9 billion (S$12 billion), funded solely by falling fuel costs, according to officials familiar with the railway budget.