February 09, 2012, 10:52 PM EST

By Lily Nonomiya

(Updates with yen sale total in the fourth paragraph.)

Feb. 10 (Bloomberg) — Japanese Finance Minister Jun Azumi said his nation’s authorities have no reservations about conducting intervention alone to combat currency swings.

“We’ve said we won’t hesitate to intervene” to counter speculative currency movements, Azumi told lawmakers in parliament in Tokyo today. “We won’t be shy at all about unilateral intervention.”

The U.S. Treasury Department criticized Japan in a December report for unilaterally selling its currency in August and October, saying the Asian nation should focus on steps to “increase the dynamism of the domestic economy.” Gains in the yen are deepening an export slump that is threatening profits at companies from Sharp Corp. to Honda Motor Co. and limiting the recovery from last year’s earthquake.

Japan’s currency traded at 77.59 as of 12:29 p.m. in Tokyo, compared with a post-World War II high of 75.35 on Oct. 31. The Finance Ministry this week said it conducted unannounced interventions in November as part of 14.3 trillion yen ($184 billion) of sales in 2011.

Weaker exports probably caused the economy to contract in the fourth quarter, analysts said ahead of the release of a gross domestic product report due Feb. 13. GDP shrank 1.4 percent in the three months ended Dec. 31 after expanding at an annualized 5.6 percent rate in the previous quarter, according to the median forecast of 25 economists surveyed by Bloomberg News.

The government said this week exports in the first 20 days of January fell about 20 percent from the previous year, the fastest decline since the same period in December 2001.

–Editors: Lily Nonomiya, Paul Panckhurst

To contact the reporter on this story: Lily Nonomiya in Tokyo at lnonomiya@bloomberg.net

To contact the editor responsible for this story: Paul Panckhurst at ppanckhurst@bloomberg.net