Credit rating companies issued a record number of downgrades this year as the March 11 earthquake, tsunami and nuclear crises pushed Japan's economy into its third recession in a decade.

Standard & Poor's lowered assessments 109 times this year, the most in at least a decade, while lifting them 14 times. The ratio of upgrades to reductions stands at 0.13, compared with 1.12 in the United States. The downgrades include the reduction in January of Japan's sovereign credit rating to AA- from AA.

Japanese corporate creditworthiness suffered as the effect of two sovereign reductions and the March 11 quake was compounded by a stronger yen and a debt crisis in Europe. The nation's companies received more downgrades than their Asian neighbors and South American counterparts combined, even though they benefit from the second-lowest borrowing costs in the developed world and rising cash reserves.