TOKYO, Sept 23 (Reuters) - Japan's government and centralbank must work closely together to avoid triggering an unwelcomeyen fall caused by a loss of market trust over the country'sfinances, Taro Kono, a key contender in the ruling partyleadership race, said on Thursday.

"If market trust over Japan's finances is lost, that couldtrigger a yen fall," Kono said. "If yen falls proceed, importcosts would rise and cause inflation," he said in an onlinedebate among the candidates in the race.

(Reporting by Leika Kihara; Editing by Giles Elgood) ((leika.kihara@thomsonreuters.com; +813-6441-1828; ReutersMessaging: leika.kihara.reuters.com@reuters.net))