TOKYO :Japanese authorities may tolerate moderate yen declines but could intervene if the currency sharply depreciates towards 160 to the dollar, said Atsushi Takeuchi, a former central bank official who was involved in Tokyo's market forays a decade ago. The yen was set for its steepest weekly drop in a year on Friday after fiscal and monetary dove Sanae Takaichi's surprise victory in a ruling party race led to receding expectations of a near-term interest rate hike by the Bank of Japan.