Singapore, June 4 (BridgeNews) - Bank of Japan Senior Deputy Governor Yutaka Yamaguchi said an increase in the rate of deflation in Japan could not be ruled out. He noted that the BOJ's ability to meet inflation targets is limited when corporate profits are slowing and bank balance sheets are weak. Speaking to the International Monetary Conference Monday, Yamaguchi said in recent months Japan's economy has seen a modest deflation of 0.5%.