"Our ratings on Indian information technology companies reflect our 'BBB+' transfer and convertibility (T&C) assessment of India. We could lower the ratings on these companies if we revise downward our T&C assessment," S&P said in a statement.
At the Bombay Stock Exchange, the Infosys scrip ended flat at Rs. 2,348.80 while TCS closed 1.92% down at Rs. 1,172.30.
The scrip of India's third largest IT company fell 7.29% at Rs.410.15 after it reported muted guidance for the April-June quarter.
The outlook revisions followed a similar action on the sovereign credit rating on India by the agency which warned of a ratings downgrade citing deteriorating economic indicators and slow progress on fiscal reforms in the backdrop of a "weakened political setting".