160 yentothedollar seen as Japan authorities39; line in sand
Japan issues fresh warning against excessive yen falls
Chance of BOJ hike in December may rise if yen keeps falling

TOKYO, Nov 7 Reuters A dollar rally triggered by Republican Donald Trump39;s victory in the U.S. presidential election could heighten pressure on the Bank of Japan to raise interest rates as soon as December to prevent the yen from sliding back toward threedecade lows.

Trump39;s victory in the U.S. presidential election unleashed sharp dollar gains, as expectations of tax cuts and tariffs on imports drove optimism about economic growth while fueling worries about inflation.

The greenback39;s strength briefly pushed the yen to a threemonth low of 154.71 on Thursday, well off a high of 140.62 hit in midSeptember.

While a weak yen gives exports a boost, it has become a headache for Japanese policymakers by pushing up fuel and food import costs and in turn hurting consumption.

Rising inflation was widely seen as one of the factors behind the massive voter swing against the ruling coalition at last month39;s general election.

Japan39;s top currency diplomat Atsushi Mimura escalated his warning against sharp yen falls on Thursday, saying authorities were ready to act against excessive currency moves.

One nightmare scenario for policymakers would be a renewed plunge in the yen towards the threedecade trough near 162 to the dollar hit in July a move that prodded the BOJ to raise interest rates…