New Delhi, Feb 22 : India will take all the steps necessary to unearth black money stashed abroad, with negotiations already on with a number of tax havens for sharing such information, President Pratibha Patil said Monday.

"India is an active part of the global efforts to facilitate exchange of tax information and take action against tax evaders," the president told the joint session of parliament to kick-off the budget session.

"My government has undertaken a number of steps to unearth unaccounted for money parked outside India. These include amendment of the Income Tax Act, 1961, to enable the central government to enter into tax agreements with non-sovereign jurisdictions."

While no official data is available on the quantum of slush funds, it is estimated that such black money stashed away by Indian nationals in tax havens overseas could be worth nearly USD 140 billion.

According to the president, steps have already been initiated for negotiating what are called agreements for exchange of information with major jurisdictions so as unearth illegal money.

"Re-negotiation of the Tax Treaty with Switzerland is in process."

According to the Organisation for Economic Cooperation and Development (OECD), India is among the 40-odd nations that have substantially implemented the globally accepted norms on exchange of information on tax.

Finance Minister Pranab Mukherjee has also ordered re-negotiation of all the 77 double-tax avoidance pacts entered into so far to get real time information and track tax evasions or stashing away of black money in other countries.