Ratings agency Moody's has lowered the long-term and short-term debt ratings of reinsurer ACE.

Under the move ACE's long-term debt rating was cut to A3 from A2, while its short-term debt was cut from Prime-2 from Prime-1.

The ratings actions signify a lowering of Moody's opinion on ACE's ability to honour its debt repayments.

Moody's said the downgrades were due to ACE's increased exposure to asbestos-related liabilities. It also cited the group's heightened exposures to reinsurance risk.