Trump cannot legally compel U.S. companies to abandon China and he gave no details on how he might proceed with any such order.

For many products sold in the United States, there are few alternatives to Chinese production, and shifting production for major goods produced there could take years and be expensive.

The following table shows the U.S. S&P 500 companies with the greatest revenue exposure to China, most of which are chipmakers. The list is based on a Refinitiv model that uses company filings where possible and on estimates where no company-reported data is available:

Company Estimated China Friday stock

Revenue Exposure move

Wynn Resorts 75% -3.8%

Qualcomm Inc 67% -3.2%

Micron Technology 57% -4.2%

Qorvo Inc 57% -3.4%

Broadcom Inc 49% -4.7%

IPG Photonics 43% -5.2%

Advanced Micro Devices 39% -5.6%

Maxim Integrated Products 35% -3.0%

Inc

A. O. Smith Corp 34% -2.4%

Amphenol Corp 32% -1.8%

In a series of tweets on Friday, Trump also said he was ordering carriers including FedEx, United Parcel Service and retailer Amazon to refuse deliveries from China of fentanyl, a synthetic opioid. Trump has accused China of failing to meet promises to stem a deluge of fentanyl into the United States

Company Estimated China Friday stock

Revenue Exposure move

FedEx Corp 7% -3.6%

United Parcel Service Inc 5% -3.4%

Trump's widening trade war and China's slowing economic expansion have hurt several other U.S. companies that in recent years have relied on the world's second largest economy to drive their sales growth:

** Apple relies on China for about 17% of its revenue and manufactures its iPhones and other products in China. Its stock dropped 4.5% on Friday after Trump's newest tweets.

** Detroit automakers General Motors Co and Ford Motor Co cut their full-year profit forecasts due to escalating tariffs

** Caterpillar Inc recently said tariffs on Chinese imports are expected to increase its material costs by up to $200 million in the second half of 2019. The heavy machinery maker plans to offset most of the higher costs with mid-year price hikes.

** Boeing Co on Aug. 8 said it is concerned about the impact of possible trade tariffs on the cost of running its supply chain, but has not yet seen any impact from U.S.-Chinese trade tensions on its business.

** General Electric Co estimated that new tariffs on its imports from China could raise its costs by up to $400 million overall, before steps to lessen the impact

** Consumer products maker Newell Brands Inc said the annualised impact of tariffs could be as much as $100 million.

(Reporting by Noel Randewich; Editing by Alden Bentley and Paul Simao)

By Noel Randewich