Foreign exchange reserves increased $623 million to $143.841 billion for the week ended August 26 when compared with $143.218 billion in the previous week, according to the weekly supplement released by the RBI on Saturday.Foreign currency assets moved up $616 million to $137.999 billion. Gold reserves and SDRs were unchanged at $4.395 billion and $4 million respectively. The Reserve Tranche Position with the IMF was up $7 million at $1.443 billion.