The reserves had increased by $39.6 million to $296.57 billion for the week ended Dec 28, 2012.
The foreign currency assets (FCA) - the biggest component of the forex reserves - went down by $951.7 million at $261.06 billion, according to the weekly statistical supplement released by the RBI.
The FCA went up by $63.9 million at $262.01 billion in the previous week.
The central bank said FCA in US$ terms included the effect of appreciation or depreciation of non-US currencies held in reserve, such as the pound sterling, euro and yen.
Gold reserves value dipped by $583.3 million and stood at $27.21 billion.
The special drawing rights (SDRs) decreased by $34.7 million to $4.40 billion during the week under review, while reserves with the International Monetary Fund (IMF) went down by $18.2 million to $2.30 billion.
The SDRs had decreased by $15.9 million to $4.43 billion during the previous week, while reserves with the IMF had went down by $8.4 million to $2.32 billion.
