Japan spent 4.46 trillion yen between Aug. 28 and Sept. 26 intervening in the currency market to weaken the yen, the Finance Ministry said Tuesday.
The government has now tossed a record 13.48 trillion yen into yen-weakening operations since the beginning of the year.
The ministry has been conducting the effort to fight the yen's ascent, which makes exporting less profitable.
Details such as the specific currencies purchased and sold will not be revealed until later.
In the first seven months of this year, Japan has broken the previous record of 7.64 trillion yen spent on interventions over the full year of 1999.
The data for September were revealed after traders said Japanese monetary authorities had stepped into the currency market again early Tuesday morning. Despite the suspected operations, however, the yen hit a new 33-month high against the dollar later in the day.
Any funds used in Tuesday's operations are not included in the September figures because the monthly data exclude the last two business days of the month.
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