Business confidence in Japan deteriorated sharply in the January-March quarter amid declines in share prices and the deceleration in the U.S. economy, according to a government survey released Tuesday.

The Cabinet Office said its quarterly survey found that its business sentiment index dropped to minus 31 in the reporting period from minus 1 in the October-December period.

The BSI is designed to measure corporate managers' confidence in the economy and is calculated by subtracting the percentage of managers saying the economy will worsen from the percentage of those saying otherwise.