President Trump tweeted late Friday that he's lobbying Lockheed Martin (LMT - Get Report) to keep a Pennsylvania helicopter plant open.

The defense contractor announced earlier this month that it plans to close the Sikorsky plant, in Coatesville, Penn. By the end of the year.

The facility employs almost 500 people in a community in the outer suburbs of Philadelphia.

Trump tweeted that he "just spoke to Marillyn Hewson, CEO of @LockheedMartin..."

Just spoke to Marillyn Hewson, CEO of @LockheedMartin, about continuing operations for the @Sikorsky in Coatesville, Pennsylvania. She will be taking it under advisement and will be making a decision soon....

— Donald J. Trump (@realDonaldTrump) June 14, 2019

Pennsylvania was a key state in Trump's 2016 election victory, where he won by a fewer than 50,000 votes out of nearly 6 million cast.

On Monday, Lockheed shares dipped after the U.S. Department of Defense said it had reached a deal to cut the price of the planemaker's F-35A fighter jet to under $80 million each. On Friday, shares ended regular trade up 0.30% at 350.14. In after-hours trade, the stock edged higher.

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