Japan's economy expanded faster than estimated in the first quarter, boosted by reconstruction spending that's poised to fade just as a worsening in Europe's crisis threatens to curtail export demand.

Gross domestic product rose an annualized 4.1 percent from the final three months of 2011, exceeding all but seven of 27 estimates in a Bloomberg News survey of economists, a Cabinet Office report showed today in Tokyo. Singapore also reported a rebound in growth last quarter, while warning about the risk of a disorderly European debt default.

Policy makers across Asia are girding for the potential impact of a Greek exit from the euro region that could roil the global financial system, with Malaysia's central bank chief seeing possible "catastrophic" consequences for Europe. South Korea said it has enough currency reserves to weather the storm, while in Japan, pressure may rise to step up monetary stimulus as the government pledged to take action against "excessive" currency moves.