U.S. manufacturing activity slumped to its weakest pace in more than a decade last month, a closely-watched survey indicated Tuesday, suggesting broader economic growth could slow amid a protracted trade war with China.

The ISM manufacturing activity index fell to 47.8 points, the survey noted, down from 49.1 points in August and the lowest level since June 2009. A mark below 50 points typically indicates contraction, and follows similarly weak readings in Europe and China for the month of September.

The US factory activity slide followed a warning from the World Trade Organization on global commerce earlier Tuesday, with the international body cutting its global merchandise trade growth forecast to 1.2% from 2.6% for 2019.

"The darkening outlook for trade is discouraging but not unexpected. Beyond their direct effects, trade conflicts heighten uncertainty, which is leading some businesses to delay the productivity-enhancing investments that are essential to raising living standards," said WTO director general Roberto Azevêdo. "Job creation may also be hampered as firms employ fewer workers to produce goods and services for export."

The employment component of the index fell 1.1 points from August to 46.3, the survey indicated, while the new orders reading edged up, to 47.3 from 47.2 points in the previous month.

The U.S. dollar index, which tracks the greenback against a basket of its global peers, pared some gains following the ISM release, but is still trading at a two-year high of 99.39. Benchmark 10-year Treasury bond yields, meanwhile, slumped to 1.651% after trading as high as 1.75% during the early European session.

The Dow Jones Industrial Average, meanwhile, pared earlier gains to turn negative on the session, falling 282 points to 26,635.36 points. the S&P 500 was marked 29 points lower at 2,947.95 points.