In the first official estimate of the economic effects of a major quake with its focus directly below Tokyo -- the centre of the nation's financial, business and political activity -- the government panel said damage could amount to 112.0 trillion yen ($1.06 trillion).

Deaths in such a scenario could total 11,000.

The panel is to draw up recommendations for lessening the damage from such a quake by around this summer.

The predicted economic effects include some 67.0 trillion yen in "direct damage" such as destruction of buildings and disruption of electricity and water supplies, and "indirect damage" of 45.0 trillion yen.

The indirect losses -- the effect on economic activity of factors such as transport disruptions -- include 25.8 trillion yen in damage to areas outside the capital.

Among 18 patterns of possible Tokyo quakes examined by the panel, the worst economic damage was seen from a magnitude 7.3 earthquake striking in Tokyo bay on a winter day at 6 p.m. with winds of 54 km an hour. A strong wind would make it harder to control fire outbreaks.

It said the greatest casualties would result if a 6.9 magnitude quake struck the western part of central Tokyo on a weekday evening at 6 p.m. -- the height of the rush hour.

It raised its estimate for deaths under that scenario to 13,000 from the 12,000 it cited in an interim report in December.

Memories are still vivid in Japan of a 7.2 magnitude quake in the western port city of Kobe that killed more than 6,400 in 1995.

The Great Kanto Earthquake of 1923, a 8.3 magnitude tremor, killed more than 140,000 people in Tokyo and neighbouring cities.