The yen was trading back above ?160 to the dollar late last week and lingered there through Monday, the market testing Japan¡¯s tolerance for a weak currency and daring it to intervene.

Safe-haven buying of the dollar due to the conflict in the Middle East and growing expectations of a rate increase in the United States following stronger-than-expected May jobs data helped weaken the yen.

By midday Monday, the Japanese currency was trading at ?160.39 to the dollar, its weakest since late April, when Tokyo last intervened to prop up the yen.