* Dollar dips to 83.09 yen on EBS; 15-year low
* Japan PM Kan wins ruling party leadership vote
* Dlr index at 1-mth low, breaks 200-day moving average
(Adds quotes, updates prices, changes dateline prvs TOKYO)
By Tamawa Desai
LONDON, Sept 14 (Reuters) - The dollar hit a 15-year low against the yen on Tuesday as Japanese Prime Minister Naoto Kan won the ruling party leadership vote, raising speculation Tokyo would not act immediately to stem the yen's rise.
Kan keeps his job after beating party heavyweight Ichiro Ozawa, who had made more strident calls to curb the yen's rise.
The dollar dipped as low as 83.09 yen on trading platform EBS as stop-loss orders were triggered on the break below 83.20 yen. By 0715 GMT, it had recovered a bit to 83.31, down 0.4 percent on the day.
"Ozawa had made comments that had been stronger on intervention, so there was a knee-jerk reaction to Kan's win. We also got a degree of political certainty from the results," said Simon Derrick, head of currency research in Bank of New York Mellon.
"The threat of intervention will hang over the market but will there be international cooperation? Probably no. So the market will continue to test Kan's resolve."
Traders said any rise in the dollar may be short-lived, with Monday's 84.43 intraday peak seen as the first point of resistance, due to expectations of more dollar selling by Japanese exporters ahead of their half-year book closing on Sept. 30.
"Clearly the market viewed the (party vote) result as yen positive, and the yen is likely to continue drifting higher both against the dollar and on the crosses," said Christian Lawrence, currency strategist at RBC Capital Markets.
The dollar hit a nine-month low against the Swiss franc and a one-month low against a basket of currencies after suffering its steepest fall against the euro in two months the previous day as investor risk appetite helped the euro.
The euro traded at $1.2882, flat on the day and keeping much of Monday's 1.6 percent gains following solid data from China and relief over new Basel III banking rules. It faced a major resistance point at $1.2920-30, a level that has blocked the currency a few times since August. (Additional reporting by Jessica Mortimer in London and Hideyuki Sano in Tokyo)