Mumbai, Sep 24 (IANS) India's foreign exchange reserves fell by $1.470 billion during the week ended September 17.The Reserve Bank of India's (RBI) forex reserves declined to $639.642 billion from $641.113 billion reported for the week ended September 10.India's forex reserves comprise foreign currency assets (FCAs), gold reserves, SDRs, and the country's reserve position with the IMF.On a weekly basis, FCAs, the largest component of the forex reserves, edged lower by $892 million to $577.986 billion.Similarly, the value of the country's gold reserves declined by $567 million to $37.103 billion.The SDR value slipped by $4 million to $19.434 billion.In addition, the country's reserve position with the IMF inched down by $8 million to $5.119 billion. --IANS rv/sn/vd