The firm issues new debt.

Rakuten Group Inc. is testing the market for a scarce supply of junk debt from the borrowing country by offering bonds worth $500 million to support the struggling mobile division of a Japanese Internet company.

The company faces a credit rating downgrade.

According to Bloomberg Intelligence analysts, “Rakuten’s bond buyback plan could signal a delay in raising funds through the listing of its banking and securities divisions, which also increases rating risk.”

The anticipated bond offering by the company will be the newest entry into Japan’s tiny junk debt market. In comparison to the global total of about $2 trillion, the amount of dollar bonds issued by speculative-grade Japanese issuers is $13.5 billion.

One of the few junk issuers on the international market is Rakuten and SoftBank Group Corp.