The "economy watchers" index fell at its fastest pace ever in March as business sentiment plunged after the March 11 disaster struck, the Cabinet Office said Friday.

The diffusion index measuring the confidence of shop clerks, hotel managers, taxi drivers and others whose jobs are considered sensitive to changes in the economy dropped to 27.7 in the reporting month compared with 48.4 in February.

Readings below 50 suggest that pessimistic views outweigh optimistic views.