Prospect Capital Corp. is offering an undisclosed amount of senior unsecured convertible notes due 2022 in an underwritten public offering.

Set to mature July 15, 2022, the notes will be convertible into the company's common shares at a conversion rate to be decided. Any interest on the notes will be payable Jan. 15 and July 15 each year, beginning July 15.

The company is expecting to use part of the offering's proceeds to occasionally buy back some of its 5.375% convertible senior notes due 2017 and its 5.75% convertible senior notes due 2018.

The offering's interest rate, conversion rate and other terms of the notes will be determined when the offering is priced.