Mumbai: India's foreign exchange (forex) reserves slumped by USD 4.29 billion to USD 316.49 billion for the week ended September 9 after rising to an all-time high of USD 320.78 billion in the previous week, official data showed.

Foreign currency assets, the biggest component of the forex reserves kitty, dropped sharply for the second consecutive week. The foreign currency assets plunged by USD 4.17 billion to USD 280.70 billion during the week under review, according to the weekly statistical supplement of the Reserve Bank of India (RBI), the country's central bank.

The foreign currency assets expressed in US dollar terms include the effect of appreciation or depreciation of non-US currencies such as the pound sterling, euro and yen held in reserve.

The assets had declined by USD 1.32 billion in the previous week. The value of special drawing rights (SDRs) dropped by USD 69 million to USD 4.54 billion and reserves with the International Monetary Fund (IMF) fell by USD 45 million to USD 2.93 billion.However, gold reserves remained unchanged at USD 28.32 billion. Gold reserves had jumped by USD 2.97 billion in the last week due to revaluation in prices.