The lower yen boosted the shares of Japanese exporters on Friday

Investors have been ditching the yen, betting that US interest rates would remain high, strengthening the dollar.

The move boosted stocks on Tokyo's leading Nikkei index, which closed up 218 points, as the cheaper yen lifted the shares of major Japanese exporters.

In late-morning trading on Friday, the yen stood at 120.37 to the dollar.

Earlier in the day, the dollar had touched a 13-month high of 120.74 yen.

"When the currency trades at 120 yen to the dollar, that's basically a signal to buy stocks," said Tatsuyuki Kawasaki, director of the equities trading division at Kaneyama Securities.

Trade surplus

A weaker yen makes Japanese exports less expensive for overseas consumers, potentially lifting the volume of sales abroad, and boosting the value of foreign earnings.

Shares in Japanese electronics components maker Kyocera, which makes more than half of its sales abroad, were among those to benefit from the drop in the yen. Shares in the firm rose by 3%.

Japan's trade surplus with the rest of the world has been growing in recent months, boosted by demand for cars and electrical goods.

The country's trade surplus leapt by 54.1% in November from a year earlier to 915.9bn yen, according to official figures released last month.