Tokyo, July 31 (Jiji Press)--The Japanese government and the Bank of Japan carried out a yen-buying, dollar-selling market intervention for the first time in about three months on Thursday night, during New York trading hours, informed sources said Friday. Japanese authorities likely conducted a surprise intervention as Finance Minister Satsuki Katayama did not issue a prior warning, as she did ahead of the previous intervention on April 30. In New York on Thursday, the dollar briefly plunged by about 5 yen to slip below 158 yen, hitting its lowest level since mid-May. When asked by reporters in Tokyo on Friday morning, Katayama declined to comment on whether Japanese authorities had intervened to prop up the yen. END [Copyright The Jiji Press, Ltd.]