(Bloomberg News) A "perfect storm" of fiscal woe in the U.S., a slowdown in China, European debt restructuring and stagnation in Japan may converge on the global economy, New York University professor Nouriel Roubini said.

There's a one-in-three chance the factors will combine to stunt growth from 2013, Roubini said in a June 11 interview in Singapore. Other possible outcomes are "anemic but OK" global growth or an "optimistic" scenario in which the expansion improves.

"There are already elements of fragility," he said. "Everybody's kicking the can down the road of too much public and private debt. The can is becoming heavier and heavier, and bigger on debt, and all these problems may come to a head by 2013 at the latest."

Elevated U.S. unemployment, a surge in oil and food prices, rising interest rates in Asia and trade disruption from Japan's record earthquake threaten to sap the world economy. Stocks worldwide have lost more than $3.3 trillion since the beginning of May, and Roubini said financial markets by the middle of next year could start worrying about a convergence of risks in 2013.

The MSCI AC World Index has tumbled 4.9 percent this month on concern recent data, including an increase in the U.S. unemployment rate to 9.1 percent in May, signal the global economy is losing steam. U.S. Treasuries rose last week, pushing two-year note yields down for a ninth week in the longest stretch of decreases since February 2008, on bets the Federal Reserve will maintain monetary stimulus.

Bond Market 'Revolt'

World expansion may slow in the second half of 2011 as "the deleveraging process continues," fiscal stimulus is withdrawn and confidence ebbs, Roubini also said.

Easing growth may spur demand for dollar assets as a "safe haven," he said in response to questions after a speech in Singapore today. The Dollar Index, which gauges the U.S. currency's value against a basket of six counterparts including the euro, yen and British pound, rose 0.1 percent as of 11:35 a.m. in Singapore, bound for a fourth straight daily increase.

Roubini is among analysts who predicted the global financial crisis of 2007-2009 that was triggered by a collapse in the value of U.S. mortgage securities.

Some of his other predictions haven't panned out, including his call on July 4, 2010, for "market surprises on the downside" in ensuing months and a weakening in economic growth. The MSCI World Index rallied 23 percent in the second half of last year, while U.S. gross domestic product gains accelerated to 2.6 percent in the third quarter and 3.1 percent in the fourth quarter from 1.7 percent in the April-to-June period.