CitiSL's stringent credit evaluation framework has helped the branch to maintain sound asset quality with zero non-performing loans since 2009, Fitch Ratings said.
However, it has also led to a highly concentrated loan book, with the top 20 largest loans accounting for 97% of total lending at end-1H17.
Fitch expects the branch to maintain sufficient capitalisation to support its business plans despite regular profit repatriations.
CitiSL's liquidity position is stable as the branch has access to inter group funding, if needed.
A downgrade of CitiSL's rating could result from Citibank, N.A.'s rating falling below Sri Lanka's IDR, although Fitch sees that as highly unlikely in the near to medium term.
Significant changes to Fitch's expectation of support from CitiBank N.A. could also have a negative impact on the rating.
Sri Lanka will be receiving support from Citibank, N.A, the consumer banking arm of US financial services subject to any regulatory constraints on remitting money into the country.