March 7 (Reuters) - Shares of large U.S. pharmaceutical companies fell on Tuesday after President Donald Trump said he was working on a "new system" to lower pricing in the drug industry.
"I am working on a new system where there will be competition in the Drug Industry. Pricing for the American people will come way down!" Trump tweeted.
Pfizer Inc shares fell 1.3 percent in premarket trading, Merck fell 1.2 percent and Amgen Inc fell 1.3 percent. (Reporting by Lewis Krauskopf in New York; Editing by Chizu Nomiyama)