HONG KONG — Asian stock markets tumbled today, following Wall Street lower as U.S. presidential election euphoria gave way to fears of a deep and protracted recession in the world's largest economy.

Japan's Nikkei stock average retreated 5.7 percent to 8,980.18, and Hong Kong's Hang Seng Index lost 6.7 percent to 13,842.99.

South Korea's benchmark Kospi index broke a five-session winning streak to dive 7 percent. Markets in Singapore, Australia and mainland China also fell.

The pullback was in line with weakness on Wall Street, where investor optimism surrounding the election of Democrat Barack Obama as president quickly evaporated in the face of gloomy economic news. The U.S. service sector, the largest component of America's gross domestic product, contracted sharply in October as new orders and employment fell.

Closer to home, a series of profit warnings from major companies such as carrier Cathay Pacific Airways Ltd. and Japan's Isuzu Motors Ltd. yanked the markets back to the reality of deteriorating economic conditions. After seeing some strong gains in recent days, many investors moved to take profits.