Credit ratings agency Moody's has revised the outlook of four Adani Group companies to 'stable' from 'negative' in view of timely debt repayments and ability to raise funds.The ratings for Adani Green Energy, Adani Green Energy Restricted Group 1, Adani Transmission, and Adani Electricity have been revised, said a report by Moody's Investors Services. The ratings for eight other Adani Group companies remain unchanged as 'stable'.