* Manufacturing data weak in China, Europe, U.S.
* Energy and materials slide as oil, copper fall
* Onyx Pharma jumps after cancer drug gets backing
* Indexes off: Dow 0.7 pct, S&P 1 pct, Nasdaq 1.2 pct (Updates to midday, changes byline)
By Rodrigo Campos
NEW YORK, June 21 (Reuters) - U.S. stocks fell on Thursday after a raft of data showed an overseas economic slowdown was adding to U.S. weakness.
Energy and materials shares led declines on Wall Street, as U.S. crude futures slipped below $80 a barrel for the first time since October and copper tumbled 2.7 percent. Both the S&P energy sector index and the materials index lost about 2 percent.
Data on Thursday showed business activity across the euro zone shrank for a fifth straight month in June and Chinese manufacturing contracted, while weaker overseas demand slowed U.S. factory growth.
“Selling today is on the idea that the manufacturing sector is weak,” said Jim Paulsen, chief investment officer at Wells Capital Management in Minneapolis. “It’s about the whole manufacturing story... reports are weak across the globe.”
Other U.S. data showed home resales fell in May and applications for unemployment insurance were higher than expected in the latest week.
Softening data globally has lifted hopes of central bank action to support the economy. On Wednesday, the U.S. Federal Reserve announced it would deliver another round of monetary stimulus and said it was ready to do even more to help an increasingly fragile U.S. economic recovery, but the move was nonetheless a disappointment to markets.
The Dow Jones industrial average fell 92.37 points, or 0.72 percent, to 12,732.02. The S&P 500 Index dropped 13.46 points, or 0.99 percent, to 1,342.23. The Nasdaq Composite lost 36.14 points, or 1.23 percent, to 2,894.31.
Semiconductor stocks weighed on the Nasdaq after chipmaker Micron Technology Inc posted a net loss for the fourth straight quarter. Micron lost 6 percent to $5.75 and the PHLX semiconductor index dropped 2.3 percent.
Celgene Corp slumped 11.6 percent to $59.36 after the company said it was withdrawing a European application for wider use of its big-selling Revlimid blood cancer drug.
Philip Morris International 2 percent to $86.78 after forecasting full-year earnings below Wall Street estimates, saying a strong dollar has hurt sales abroad. Philip Morris disappointing news followed similar outlooks from fellow multinationals PepsiCo and Procter & Gamble.
Onyx Pharmaceuticals Inc surged almost 40 percent after U.S. drug advisers backed the company’s drug for cancer patients. Ligand Pharmaceuticals Inc, which stands to receive royalties from sales of the drug, gained 9.1 percent to $15.88. (Reporting by Rodrigo Campos; Editing by Chizu Nomiyama)