State Bank of India , the country's biggest lender, will need to raise more funds beyond the $1.6 billion assured by the government to meet rising demand for loans in an expanding economy, Chief Financial Officer Diwakar Gupta said.

The bank needs Rs 15,000 crore, including retained profit, a year, Gupta said on Tuesday.

"We will definitely need to raise money in the next financial year. We will have to see if the government is putting more money," he told Reuters by telephone.

On Monday, the bank said the government would inject Rs 7,900 crore by buying shares through a preferential allotment.

The investment will likely raise the government's holding by 2-2.25% from 59% currently, he said.