Forex exchange reserves increased by $394 million to $131.015 billion for the week ended December 24 as against the previous week's $130.621 billion, according to the weekly supplement issued by the Reserve Bank of India.Foreign currency assets rose $383 million to $125.049 billion from $124.666 billion touched on December 17.Gold reserves and SDRs were unchanged at $4.540 billion and $5 million, respectively.The Reserve Tranche Position with the IMF was up $11 million to $1.421 billion.