China's economic slowdown is weighing on corporate earnings across Asia and around the world as businesses and consumers tighten their purse strings in a vital market.

Nikkei tallied earnings and analyst forecasts for the October-December quarter for leading companies in the U.S., Europe, China, Japan and the rest of Asia. China suffered a particularly sharp slowdown, with sales slumping roughly 30% on the year. Net profit sank 9%, marking the first decline on a quarterly basis in two years and the largest drop since April-June 2016.

China's troubles have rippled out to hit surrounding Asian markets. Net profit slumped 9% at Japanese companies and 18% at businesses in Asia excluding China and Japan.