NEW YORK - Worries about economic growth prospects hit global stock markets on Friday, causing sharp price drops on both sides of the Atlantic.

In bloodletting on Wall Street, US stocks suffered their worst day since early January.

The closely watched "yield curve" flashed a warning sign that a recession could be looming while monthly US, French and German manufacturing indices all fell -- rattling investors who were already uneasy after this week's surprisingly weak outlook from the Federal Reserve.

"A series of worse-than-expected economic releases from Europe have sounded the alarm bell not just for the bloc, but also the global economy, by providing further evidence of a worldwide slowdown in economic activity," said XTB analyst David Cheetham.

The so-called yield curve, which tracks the spread between short- and longer-term rates on US Treasury bonds, briefly inverted on Friday, with yields on three month bonds falling below those for 10-year notes -- the first time this had happened since before the global financial crisis in 2007.

The yield curve is closely watched since it has inverted prior to recessions in recent decades.

Also weighing on the benchmark Dow Jones Industrial Average were poor showings for Boeing and Nike, which fell 2.8 percent and 6.6 percent.

An Indonesian air carrier on Friday became the first to announce it was canceling a multi-billion-dollar order of 737 MAX aircraft in the wake of recent fatal crashes in which nearly 350 people perished.

In foreign exchange, sterling rose again after Brussels gave Britain a Brexit deadline extension.

Signs of a weak first quarter for the eurozone also mounted on Friday as a closely-watched survey pointed to March output being dragged further down by manufacturing weakness, especially in Germany, Europe's largest economy.