BEIJING—China's economic engine sputtered in August as industrial production growth slowed to its lowest level since the 2008 global financial crisis, according to data released Saturday, increasing the chance that Beijing will step up stimulus measures to bolster the world's second-largest economy.

Economists said the sharp deceleration in industrial output, along with weaker fixed-asset investment, retail and real estate sales data, is likely to rattle regional stock markets Monday as Beijing struggles to reach its annual...