A record number of Japanese people literally worked themselves to death last year despite a government campaign to ease the country's notorious office hours.

Some 355 workers fell severely ill or died from overwork in the year to March, the highest figure on record and 7.6 percent up from the previous year, the Ministry of Health, Welfare and Labour said.

Of the total, 147 people died, many from strokes or heart attacks.

Death from overwork grew so common during Japan's post-World War II economic miracle that a word was coined for it, "karoshi."

The government has tried to address the problem by promoting telecommuting and encouraging workers to take leave when they start families or need to care for elderly parents.

But as Japan's economy posts a record-long expansion, critics point to the rising number of part-time jobs, saying new employees lack the security that would allow them to resist pressure to overwork.

The labour ministry said it rejected nearly half of the record 938 worker claims filed in the last financial year seeking compensation for suspected illness or death from overwork.

Separately, another 819 workers contended they became mentally ill due to overwork, with 205 cases given compensation, according to the ministry data released on Wednesday.

Mentally troubled workers killed themselves or attempted to do so in 176 cases, of which a record 66 cases were found eligible for benefits, the ministry report said.

The number of Japanese who killed themselves because of work jumped 52 percent last year, while work-induced mental illness also hit a record high, according to Health Ministry official Junichiro Kurashige.

Compensation paid to the families of workers who committed suicide due to work-related stress was paid out in a record 65 cases in 2006, compared to 42 the previous year, said Kurashige.

Japan's suicide rate is among the highest in the industrialized world. More than 32,000 people took their own lives in 2004, most of them older people suffering financial woes as the country struggled through a decade of economic stagnation.

The Japanese government has earmarked substantial budget for programs to help those with depression and other mental illnesses.