Japan appointed a new top foreign exchange diplomat on Friday as the yen plumbed a 38-year low against the dollar, heightening expectations of imminent market intervention by Tokyo to shore up the battered currency.

Atsushi Mimura, a financial regulation veteran, replaces Masato Kanda, who launched the biggest yen-buying intervention on record this year.

The change is part of a regular personnel reshuffle conducted every year and comes as officials ramped up their warnings about intervention.