Fitch Ratings has affirmed NTPC's (NSE:NTPC, BOM:532555) long-term foreign- and local-currency issuer default ratings (IDRs) at BBB-, according to a statement issued on Thursday.

The ratings agency has also kept the outlook for the state-owned power producer at stable.

The agency has also affirmed the BBB- ratings on the company's $6 billion medium-term note program and the notes issued under the program.

"NTPC's Standalone Credit Profile (SCP) of 'bbb' is underpinned by its regulated business model that enjoys high revenue and profit visibility as long as its plants are available, irrespective of actual off-take and fuel price fluctuations," Fitch said.