MBIA, the world’s largest bond insurer, slashed its dividend on Wednesday and said it planned to raise $1bn of debt to boost capital and preserve its crucial triple A rating.

The bond insurer cut its quarterly dividend more than 60 per cent to 13 cents a share, in a move that MBIA said would save the company $80m a year. MBIA’s shares tumbled 14 per cent on the news, in spite of indications that the plan would safeguard the company’s top-notch ratings.