Kansai Electric Power Co. is planning to sell ¥100 billion in bonds Thursday, five times the amount originally planned, according to a source with direct knowledge of the matter.

The nation's second-biggest power utility told investors it will price the five-year notes to yield 63 basis points more than similar-maturity government debt, according to the source, who asked not to be identified because the information is private.

The utility initially planned to sell about ¥20 billion in notes at a spread of 58 to 70 basis points, the source said.

Power companies are returning to the bond market with ¥125 billion in debt sales this year. Offerings by the utilities dried up due to the Fukushima nuclear crisis that started in March 2011, reducing the sales 92 percent to ¥95 billion last year, according to data compiled by Bloomberg.

Kepco is currently marketing a bond sale, spokesman Yusuke Inoue said, declining comment on the details of the offering.

The utility raised ¥30 billion from a sale of 1.285 percent 10-year notes in December 2010.