Scottish and Southern Energy has challenged Moody's Investors Service's decision to put its credit rating on review for a downgrade in a move that draws the spotlight onto rating agencies and their role in the international capital markets.

The UK utility, which had £2.2bn (€3.2bn) of net debt at the end of March, today hit out at a decision by Moody's, one of the world's biggest credit rating agencies, to place its Aa3 rating on review for possible downgrade on Monday.