NEW YORK (Bloomberg) - Bermuda-based CIFG Guaranty lost its AAA bond insurer rating at Standard & Poor's (S&P) because of losses on sub-prime-mortgage securities.

CIFG was cut four levels to A+ to reflect the company's "scaled-back underwriting activity, turnover of senior staff, and recent other rating downgrades," New York-based S&P said in a statement yesterday. CIFG insured $95 billion of debt as of year- end, according to its website. The ratings outlook is negative.