Japan's leading shares have risen by almost 3% after authorities intervened in the currency markets to weaken the value of the yen¹ against the dollar.

日本当局干预货币市场以降低日元对美元汇率，各主要股票因此上涨几乎3%。

The central bank stepped in to sell yen and buy dollars, a day after the yen hit a 15-year high against the dollar.

It is the first time in six years that the Bank of Japan has intervened, and further action has not been ruled out（排除，取消） .

A strong yen makes Japanese exports more expensive, and reduces profits when earnings² are repatriated³.

In early trading on Wednesday, the dollar rose to 85 yen, after hitting 83.09 yen on Tuesday.

Investors⁴ welcomed the currency move, sending Japan's Nikkei share index up by 256.50 points, or 2.9%, to 9,555.53.

The yen had spiked⁵ after news filtered through that Prime Minister Naoto Kan had survived a leadership challenge from rival Ichiro Ozawa.

Traders had reckoned（测算，估计） Mr Kan would be less likely than Mr Ozawa to take measures to weaken the yen.

Economic harm

But in a brief news conference, Finance Minister Yoshihiko Noda said: "We have conducted an intervention⁶ in order to suppress excessive fluctuations⁷（波动，变动） in the currency market.

"We will closely monitor currency developments, and take firm action including intervention.

"Our country's economy is still in a very severe situation with continued deflation," he added.

The yen's rapid appreciation⁸ "harms the stability of the economy and finances. We cannot tolerate it."

The record low for the dollar is 79.75 yen, reached in April 1995.

Mr Noda did not reveal the size of the intervention, although the Dow Jones news agency reported that Japan's Ministry⁹ of Finance had initially¹⁰ sold between 200bn and 300bn yen ($2.4bn-$3.6bn; £1.5bn-£2.3bn).

A recent government survey suggested many companies were considering moving production overseas if the yen stayed high.