Japan's finance ministry said Monday it conducted a coordinated yen-buying intervention with the U.S. Treasury on Friday.

Banks told to prepare for potential operation to buy Japanese currency

Japan and the U.S. may unveil a joint policy next week to defend the yen after record interventions in April and May.

Japan's Finance Minister plans to reveal a cooperation with Washington regarding currency market interventions aimed at arresting the yen's drastic decline to levels not seen in…