The collapse in exports may push sentiment among the nation's largest manufacturers to its lowest level in more than 30 years, triggering more investment cuts and job losses.

The Bank of Japan's "tankan" survey, an index that measures confidence among large makers of cars and electronics, will slide to minus 55 for March from minus 24 in December when it is released next Wednesday, economists predict.

That would be the lowest since 1975 and the biggest drop since the BOJ started the survey. A negative number means pessimists outnumber optimists.