"The stable outlook on SLT reflects the country risk factors," S&P said.
"Any downward movement of the sovereign ratings could prompt a reduction in the transfer and convertibility risk assessment or deterioration in the country risk factors, which in turn could result in a downgrade on SLT."
The rating could be pressured if it had limitation on remitting funds for debt repayment, its business risk profile deteriorates as a result of higher competition or regulatory constraints, or if is financial risk profile "materially deteriorates because of any shareholder-friendly action," S&P said.
An improvement in the government's rating or outlook which would improve the transfer and convertibility risk assessment for Sri Lanka, could also result in a rating upgrade.
But SLT, the country's largest fixed access operators which also owns a mobile unit, has a long term rating of 'B+' a notch higher than the sovereign.
"The ratings on SLT reflect the weak economic situation in the