Japan spent a record 2.8 trillion yen ($19.7 billion) on foreign exchange market interventions last week to shore up the yen, Finance Ministry data showed Friday, draining nearly 15% of the funds available for interventions, Reuters reported

This is the first intervention in 24 years to sell the dollar and buy the yen in Japan in an attempt to halt the currency's sharp weakening.

The intervention, made after the yen fell to a 24-year low of nearly 146 per dollar, caused a sharp rebound of more than 5 yen per dollar from that low, although the currency has since fallen back to 144.25.

According to data on foreign exchange reserves released Sept. 7, Japan had about $1.3 trillion in reserves, the second-largest after China, of which $135.5 billion was in the form of deposits placed with foreign central banks and the Bank for International Settlements (BIS).

If deposits dried up, Japan would have to invest about $1.04 trillion in its securities. Of the major types of foreign assets held by Japan, deposits and securities are the most liquid and can be immediately converted into cash. Other assets include gold, reserves in the International Monetary Fund (IMF) and IMF Special Drawing Rights (SDRs), although getting dollars from these assets will take time, analysts said.