"SFC's ratings reflect its long operating history and sustained strong capital structure, as well as its relatively sound credit control systems and processes," Fitch said in a statement.
"The ratings are however constrained by SFC's evolving economies of scale and relatively low market share in core operations in relation to some of its larger peers."
The proposed debt issue has a five-year tenure, and Fitch said expects it to be raised at a fixed coupon rate, enabling SFC to minimise interest rate risk on its loan book.
The debenture will be used to finance lending operations as well as to settle existing debt, and is expected to be listed on the Colombo Stock Exchange.
SFC is a mid-sized registered finance company (RFC) with an asset base of 6.2 billion rupees at December