NEW DELHI: After downgrading India’s sovereign outlook, Moody’s Investors Service on Friday downgraded its view to 'negative' from 'stable' on many top Indian companies, including SBI, HDFC Bank , TCS, Infosys BPCL , NTPC, NHAI and GAIL.Moody’s has downgraded outlook on companies belonging to information technology, infrastructure as well as oil and gas sectors. In total, the rating agency on Friday cut outlook on 21 Indian firms.Other financial institutions that have seen a downgrade are Exim Bank, Hero FinCorp, Hudco and Indian Railway Finance Corporation (IRFC).However, the agency kept rating and outlook unchanged on Bank of India, Canara Bank , Oriental Bank of Commerce, Syndicate Bank and Union Bank of India.Ratings of the above-mentioned financial institutions are unlikely to be upgraded in the next 12-18 months, Moody’s said.The agency also downgraded the outlook on eight non-financial corporates to negative from stable. They are BPCL, HPCL, Indian Oil, ONGC, Oil India , Petronet LNG, Infosys and Tata Consultancy Services.It also downgraded outlook on a number of sovereign-linked infrastructure companies. They include NTPC, NHPC, NHAI, GAIL, Power Grid, Adani Green and Adani Transmission.In case of Exim Bank, Hudco, IRFC and SBI, Moody’s Investors Service said close links between these four companies and the government is the key reason for their downgrade. Moody’s believes that these companies will receive government support in times of need.For HDFC Bank, it reasoned that due to the “strong linkages between a bank's business and the sovereign credit profile, including by way of large direct exposure to government debt and exposure to common underlying operating conditions, the Baseline Credit Assessment (BCA) of a bank is capped at the sovereign rating of the country that it operates in”.“Moody's does not have any particular governance concern for all the issuers impacted by today's rating action. Moody's does not apply any corporate behavior adjustment to the banks and views their risk management framework as consistent and commensurate with their risk appetite,” the New York-based rating agency said in a release."Ratings for Infosys and TCS are constrained to no more than two notches above the sovereign rating. Therefore a sovereign rating downgrade will also result in downgrade of the A3 ratings of Infosys and TCS," says Kaustubh Chaubal, a Moody's Vice President -- Senior Credit Officer.Moody’s earlier downgraded India’s outlook from ‘stable’ to ‘negative’. The rating agency said its outlook partly reflects lower effectiveness of the government and policy in addressing long-standing economic and institutional weaknesses than it had previously estimated. This is leading to a gradual rise in debt burden from already high levels.Meanwhile, Moody's has also upgraded the Baseline Credit Assessment (BCA) of GAIL to ‘baa2’ from ‘baa3’, based on its expectation that the company will maintain strong financial metrics over the next 2-3 years; a situation which is more consistent with a baa2 standalone profile.