The Japanese yen¹ fell to its lowest level against the US dollar in seven months.

日元对美元汇率降至近七个月以来最低。

Part of the reason for the fall is the Bank of Japan's surprise increase of its stimulus² measures.

The yen has fallen by 3.7% against the greenback（美钞） since the 14 February move.

A strong yen has hurt profit outlooks for Japanese manufacturers, with some focussing on overseas production.

Other firms had used to strong yen to go on buying sprees（抢购） overseas.

The dollar stood at 80.30 yen on Thursday, having risen to 80.406 overnight - its highest since July.

The Bank of Japan (BOJ) expand its asset（资产，优点） purchase programme by 10tn yen ($130bn; £83bn) in an effort to boost growth.

The BOJ also left the cost of borrowing unchanged at between zero and 0.1%.

The BBC's Tokyo correspondent Roland Buerk says another factor is the strengthening of the US dollar, after better than expected economic data out the US.

But he says the yen's decline may not alleviate³（减轻，缓和） the troubles of Japanese businesses just yet.

"Back in 2007 the yen was at 117 to the dollar not 80 like it is today, so while some depreciation⁴（折旧，贬值） like this is welcome it probably doesn't go far enough for exporters."

Carmakers, such as Toyota, Honda and Mitsubishi, have been some of the worst hit by the strong yen as it makes their products less competitive abroad.