Mumbai, Oct 8 (IANS): India's foreign exchange (forex) reserves dropped by $1.22 billion at $311.48 billion for the week ended Sep 30, registering a sharp decline for the second straight week largely due to revaluation of non-dollar assets, official data showed.

The forex reserves had slumped by $4.05 billion during the week ended Sep 23. The reserves have declined for the third time in the last four weeks under review.

The country's foreign exchange reserves kitty has shrunk by $9.30 billion in the last four weeks after swelling to an all-time high of $320.78 billion for the week ended Sep 2.

Foreign currency assets, the biggest component of the forex reserves kitty, fell by $1.23 billion to $275.69 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.

Reserves with the International Monetary Fund (IMF) dropped by $345 million to $2.61 billion.

However, the value of gold reserves rose by $348 million to a record high of $28.66 billion.

The value of special drawing rights (SDRs) rose by $7 million to $4.50 billion during the week ended Sep 30.