Sock maker Fukusuke Corp. will file for court protection from creditors with debts of about 40 billion yen as sluggish consumer spending takes its toll on sales of socks and underwear, sources familiar with the case said Saturday.

Fukusuke will file the application with the Osaka District Court under the Civil Rehabilitation Law as early as Sunday, the sources said.

Fukusuke reported a group net loss for the year ended March 31, the third net loss in as many years, leaving it with a negative net worth of 3.1 billion yen, the first negative net worth since its listing in 1949.

Established in 1882 as a maker of traditional Japanese socks, known as "tabi," Fukusuke makes mainly socks and underwear.